Visual F# 100 Examples: Example Number 6

Problem. Create an application that will display the surface area of a cube. The surface area of a cube can be computed by multiplying the inputted side by itself and multiplying the product by 6.

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. //creates a new form  
10. let cubeform=new Form(Text="Compute the Surface Area of a Cube", Size=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. //creates our controls  
12. let n1label=new Label(Text="Enter a side value:",Location=new System.Drawing.Point(0,20),AutoSize=true)  
13. let firsttextbox=new TextBox(Location=new System.Drawing.Point(120, 20))  
14. let n2label=new Label(Text="Surface area of a cube:", Location=new System.Drawing.Point(0, 90),AutoSize=true)  
15. //creates a label that will display the result of the computation  
16. let anslabel=new Label(Location=new System.Drawing.Point(140, 90), BorderStyle=BorderStyle.FixedSingle)  
17. //make our buttons  
18. let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 130))  
19. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 130))  
20. //add the controls into the form  
21. cubeform.Controls.Add(n1label)  
22. cubeform.Controls.Add(firsttextbox)  
23. cubeform.Controls.Add(n2label)  
24. cubeform.Controls.Add(anslabel)  
25. cubeform.Controls.Add(computebutton)  
26. cubeform.Controls.Add(exitbutton)  
27.   
28. //when the compute button is clicked  
29. computebutton.Click.Add(fun ans->  
30. let sidevalue=Convert.ToDouble(firsttextbox.Text)  
31. let areaofacube=6.00*(sidevalue*sidevalue)  
32.   
33. //display the areaofacube value in the anslabel  
34. anslabel.Text<-Convert.ToString(areaofacube))  
35.  //when the exit button is clicked, close the form              
36. exitbutton.Click.Add(fun exit -> cubeform.Close())    
37. Application.Run(cubeform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
//creates a new form
let cubeform=new Form(Text="Compute the Surface Area of a Cube", Size=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
//creates our controls
let n1label=new Label(Text="Enter a side value:",Location=new System.Drawing.Point(0,20),AutoSize=true)
let firsttextbox=new TextBox(Location=new System.Drawing.Point(120, 20))
let n2label=new Label(Text="Surface area of a cube:", Location=new System.Drawing.Point(0, 90),AutoSize=true)
//creates a label that will display the result of the computation
let anslabel=new Label(Location=new System.Drawing.Point(140, 90), BorderStyle=BorderStyle.FixedSingle)
//make our buttons
let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 130))
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 130))
//add the controls into the form
cubeform.Controls.Add(n1label)
cubeform.Controls.Add(firsttextbox)
cubeform.Controls.Add(n2label)
cubeform.Controls.Add(anslabel)
cubeform.Controls.Add(computebutton)
cubeform.Controls.Add(exitbutton)

//when the compute button is clicked
computebutton.Click.Add(fun ans->
let sidevalue=Convert.ToDouble(firsttextbox.Text)
let areaofacube=6.00*(sidevalue*sidevalue)

//display the areaofacube value in the anslabel
anslabel.Text<-Convert.ToString(areaofacube))
 //when the exit button is clicked, close the form            
exitbutton.Click.Add(fun exit -> cubeform.Close())  
Application.Run(cubeform)

We'll be adding some new controls after our tenth example:)

Visual F# 100 Examples:Example Number 5

Problem: Design an application that will ask a length value, height value, and width value and display the volume of the prism.

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. //creates our controls  
10. let prismform=new Form(Text="Compute the Volume of a Prism", Size=new System.Drawing.Size(300, 330),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. let n1label=new Label(Text="Length value:",Location=new System.Drawing.Point(0,20),AutoSize=true)  
12. let lenghttxtbox=new TextBox(Location=new System.Drawing.Point(80, 20))  
13. let n2label=new Label(Text="Width value:", Location=new System.Drawing.Point(0,50),AutoSize=true)  
14. let widthtxtbox=new TextBox(Location=new System.Drawing.Point(80,50))  
15. let n3label=new Label(Text="Height value:", Location=new System.Drawing.Point(0, 90),AutoSize=true)  
16. let heighttxtbox=new TextBox(Location=new System.Drawing.Point(130, 90))  
17.   
18. let n4label=new Label(Text="Prisms volume:", Location=new System.Drawing.Point(0, 180),AutoSize=true)  
19. let prismlabel=new Label(Location=new System.Drawing.Point(130, 180),BorderStyle=BorderStyle.FixedSingle)  
20. let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 250))  
21. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 250))  
22.   
23. //add the controls into the form  
24. prismform.Controls.Add(n1label)  
25. prismform.Controls.Add(lenghttxtbox)  
26. prismform.Controls.Add(n2label)  
27. prismform.Controls.Add(widthtxtbox)  
28. prismform.Controls.Add(n3label)  
29. prismform.Controls.Add(heighttxtbox)  
30. prismform.Controls.Add(n4label)  
31. prismform.Controls.Add(prismlabel)  
32. prismform.Controls.Add(computebutton)  
33. prismform.Controls.Add(exitbutton)  
34.   
35. //when the compute button is clicked  
36. computebutton.Click.Add(fun compute->  
37. //assign the data inputted in each control to each corresponding variables  
38. //compute the volume using the formula volume=lengthvalue*widthvalue*heightvalue  
39. //display the result on outcome on their assigned controls  
40. let lenghtvalue=Convert.ToDouble(lenghttxtbox.Text)  
41. let widthvalue=Convert.ToDouble(widthtxtbox.Text)  
42. let heightvalue=Convert.ToDouble(heighttxtbox.Text)  
43. let prismvol=lenghtvalue*widthvalue*heightvalue  
44. prismlabel.Text<-Convert.ToString(prismvol))  
45.  //when the exit button is clicked, close the form              
46. exitbutton.Click.Add(fun exit -> prismform.Close())    
47. Application.Run(prismform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
//creates our controls
let prismform=new Form(Text="Compute the Volume of a Prism", Size=new System.Drawing.Size(300, 330),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
let n1label=new Label(Text="Length value:",Location=new System.Drawing.Point(0,20),AutoSize=true)
let lenghttxtbox=new TextBox(Location=new System.Drawing.Point(80, 20))
let n2label=new Label(Text="Width value:", Location=new System.Drawing.Point(0,50),AutoSize=true)
let widthtxtbox=new TextBox(Location=new System.Drawing.Point(80,50))
let n3label=new Label(Text="Height value:", Location=new System.Drawing.Point(0, 90),AutoSize=true)
let heighttxtbox=new TextBox(Location=new System.Drawing.Point(130, 90))

let n4label=new Label(Text="Prisms volume:", Location=new System.Drawing.Point(0, 180),AutoSize=true)
let prismlabel=new Label(Location=new System.Drawing.Point(130, 180),BorderStyle=BorderStyle.FixedSingle)
let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 250))
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 250))

//add the controls into the form
prismform.Controls.Add(n1label)
prismform.Controls.Add(lenghttxtbox)
prismform.Controls.Add(n2label)
prismform.Controls.Add(widthtxtbox)
prismform.Controls.Add(n3label)
prismform.Controls.Add(heighttxtbox)
prismform.Controls.Add(n4label)
prismform.Controls.Add(prismlabel)
prismform.Controls.Add(computebutton)
prismform.Controls.Add(exitbutton)

//when the compute button is clicked
computebutton.Click.Add(fun compute->
//assign the data inputted in each control to each corresponding variables
//compute the volume using the formula volume=lengthvalue*widthvalue*heightvalue
//display the result on outcome on their assigned controls
let lenghtvalue=Convert.ToDouble(lenghttxtbox.Text)
let widthvalue=Convert.ToDouble(widthtxtbox.Text)
let heightvalue=Convert.ToDouble(heighttxtbox.Text)
let prismvol=lenghtvalue*widthvalue*heightvalue
prismlabel.Text<-Convert.ToString(prismvol))
 //when the exit button is clicked, close the form            
exitbutton.Click.Add(fun exit -> prismform.Close())  
Application.Run(prismform)

Visual F# 100 Examples: Example Number 4

Problem: Make an application that will display the area of an annulus (overlapping circles). The area of an annulus can be calculated by subtracting the area of a small circle from the area of a larger circle.

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. //creates a new form  
10. let annulform=new Form(Text="Dislay the Area of an Annulus", Size=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. //creates our controls  
12. let n1label=new Label(Text="Area of a large circle:",Location=new System.Drawing.Point(0,20),AutoSize=true)  
13. let firsttextbox=new TextBox(Location=new System.Drawing.Point(120, 20))  
14. let n2label=new Label(Text="Area of a small circle:", Location=new System.Drawing.Point(0,50),AutoSize=true)  
15. let secondtextbox=new TextBox(Location=new System.Drawing.Point(120,50))  
16. let n3label=new Label(Text="Area of an annulus:", Location=new System.Drawing.Point(0, 90),AutoSize=true)  
17. //creates a label that will display the result of the computation  
18. let anslabel=new Label(Location=new System.Drawing.Point(120, 90), BorderStyle=BorderStyle.FixedSingle)  
19. //make our buttons  
20. let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 130))  
21. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 130))  
22. //add the controls into the form  
23. annulform.Controls.Add(n1label)  
24. annulform.Controls.Add(firsttextbox)  
25. annulform.Controls.Add(n2label)  
26. annulform.Controls.Add(secondtextbox)  
27. annulform.Controls.Add(n3label)  
28. annulform.Controls.Add(anslabel)  
29. annulform.Controls.Add(computebutton)  
30. annulform.Controls.Add(exitbutton)  
31.   
32. //when the compute button is clicked  
33. computebutton.Click.Add(fun ans ->  
34. let areaoflargecircle=Convert.ToDouble(firsttextbox.Text)  
35. let areaofsmallcircle=Convert.ToDouble(secondtextbox.Text)  
36. let areaofannulus=areaoflargecircle-areaofsmallcircle  
37.   
38. //display the area of annulus value in the anslabel  
39. anslabel.Text<-Convert.ToString(areaofannulus))  
40.  //when the exit button is clicked, close the form              
41. exitbutton.Click.Add(fun exit -> annulform.Close())    
42. Application.Run(annulform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
//creates a new form
let annulform=new Form(Text="Dislay the Area of an Annulus", Size=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
//creates our controls
let n1label=new Label(Text="Area of a large circle:",Location=new System.Drawing.Point(0,20),AutoSize=true)
let firsttextbox=new TextBox(Location=new System.Drawing.Point(120, 20))
let n2label=new Label(Text="Area of a small circle:", Location=new System.Drawing.Point(0,50),AutoSize=true)
let secondtextbox=new TextBox(Location=new System.Drawing.Point(120,50))
let n3label=new Label(Text="Area of an annulus:", Location=new System.Drawing.Point(0, 90),AutoSize=true)
//creates a label that will display the result of the computation
let anslabel=new Label(Location=new System.Drawing.Point(120, 90), BorderStyle=BorderStyle.FixedSingle)
//make our buttons
let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 130))
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 130))
//add the controls into the form
annulform.Controls.Add(n1label)
annulform.Controls.Add(firsttextbox)
annulform.Controls.Add(n2label)
annulform.Controls.Add(secondtextbox)
annulform.Controls.Add(n3label)
annulform.Controls.Add(anslabel)
annulform.Controls.Add(computebutton)
annulform.Controls.Add(exitbutton)

//when the compute button is clicked
computebutton.Click.Add(fun ans ->
let areaoflargecircle=Convert.ToDouble(firsttextbox.Text)
let areaofsmallcircle=Convert.ToDouble(secondtextbox.Text)
let areaofannulus=areaoflargecircle-areaofsmallcircle

//display the area of annulus value in the anslabel
anslabel.Text<-Convert.ToString(areaofannulus))
 //when the exit button is clicked, close the form            
exitbutton.Click.Add(fun exit -> annulform.Close())  
Application.Run(annulform)

Visual F# 100 Examples:Example Number 3

We are now on our third example of our planned 100 Visual F# windows form applications learning examples. If you noticed we are just using basic controls such as textboxes, labels, and buttons. We will add some new controls in our future examples. Meanwhile, try the following:

Problem: Create an application that will ask the name of an object or material, its voltage and current values then display its electrical resistance.

Solution:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. //creates our controls  
10. let resistanceform=new Form(Text="Compute Resistance", Size=new System.Drawing.Size(300, 330),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. let n1label=new Label(Text="Material:",Location=new System.Drawing.Point(0,20),AutoSize=true)  
12. let materialtextbox=new TextBox(Location=new System.Drawing.Point(80, 20))  
13. let n2label=new Label(Text="Current(volts):", Location=new System.Drawing.Point(0,50),AutoSize=true)  
14. let currenttextbox=new TextBox(Location=new System.Drawing.Point(80,50))  
15. let n3label=new Label(Text="Voltage(amperes):", Location=new System.Drawing.Point(0, 90),AutoSize=true)  
16. let voltstextbox=new TextBox(Location=new System.Drawing.Point(130, 90))  
17.   
18. let n4label=new Label(Text="Material:", Location=new System.Drawing.Point(0, 180),AutoSize=true)  
19. let materiallabel=new Label(Location=new System.Drawing.Point(130, 180),BorderStyle=BorderStyle.FixedSingle)  
20. let n5label=new Label(Text="Resistance(ohms):", Location=new System.Drawing.Point(0, 210),AutoSize=true)  
21. let resistancelabel=new Label(Location=new System.Drawing.Point(130, 210),BorderStyle=BorderStyle.FixedSingle)  
22. let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 250))  
23. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 250))  
24.   
25. //add the controls into the form  
26. resistanceform.Controls.Add(n1label)  
27. resistanceform.Controls.Add(materialtextbox)  
28. resistanceform.Controls.Add(n2label)  
29. resistanceform.Controls.Add(currenttextbox)  
30. resistanceform.Controls.Add(n3label)  
31. resistanceform.Controls.Add(voltstextbox)  
32. resistanceform.Controls.Add(n4label)  
33. resistanceform.Controls.Add(materiallabel)  
34. resistanceform.Controls.Add(n5label)  
35. resistanceform.Controls.Add(resistancelabel)  
36. resistanceform.Controls.Add(computebutton)  
37. resistanceform.Controls.Add(exitbutton)  
38.   
39. //when the compute button is clicked  
40. computebutton.Click.Add(fun compute->  
41. //assign the data inputted in each control to each corresponding variables  
42. //compute the resistance using the formula resistance=voltage divided by current  
43. //display the result on outcome on their assigned controls  
44. let material=materialtextbox.Text  
45. let current=Convert.ToDouble(currenttextbox.Text)  
46. let voltage=Convert.ToDouble(voltstextbox.Text)  
47. let resistance=voltage/current  
48. materiallabel.Text<-material  
49. resistancelabel.Text<-Convert.ToString(resistance))  
50.  //when the exit button is clicked, close the form              
51. exitbutton.Click.Add(fun exit -> resistanceform.Close())    
52. Application.Run(resistanceform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
//creates our controls
let resistanceform=new Form(Text="Compute Resistance", Size=new System.Drawing.Size(300, 330),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
let n1label=new Label(Text="Material:",Location=new System.Drawing.Point(0,20),AutoSize=true)
let materialtextbox=new TextBox(Location=new System.Drawing.Point(80, 20))
let n2label=new Label(Text="Current(volts):", Location=new System.Drawing.Point(0,50),AutoSize=true)
let currenttextbox=new TextBox(Location=new System.Drawing.Point(80,50))
let n3label=new Label(Text="Voltage(amperes):", Location=new System.Drawing.Point(0, 90),AutoSize=true)
let voltstextbox=new TextBox(Location=new System.Drawing.Point(130, 90))

let n4label=new Label(Text="Material:", Location=new System.Drawing.Point(0, 180),AutoSize=true)
let materiallabel=new Label(Location=new System.Drawing.Point(130, 180),BorderStyle=BorderStyle.FixedSingle)
let n5label=new Label(Text="Resistance(ohms):", Location=new System.Drawing.Point(0, 210),AutoSize=true)
let resistancelabel=new Label(Location=new System.Drawing.Point(130, 210),BorderStyle=BorderStyle.FixedSingle)
let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 250))
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 250))

//add the controls into the form
resistanceform.Controls.Add(n1label)
resistanceform.Controls.Add(materialtextbox)
resistanceform.Controls.Add(n2label)
resistanceform.Controls.Add(currenttextbox)
resistanceform.Controls.Add(n3label)
resistanceform.Controls.Add(voltstextbox)
resistanceform.Controls.Add(n4label)
resistanceform.Controls.Add(materiallabel)
resistanceform.Controls.Add(n5label)
resistanceform.Controls.Add(resistancelabel)
resistanceform.Controls.Add(computebutton)
resistanceform.Controls.Add(exitbutton)

//when the compute button is clicked
computebutton.Click.Add(fun compute->
//assign the data inputted in each control to each corresponding variables
//compute the resistance using the formula resistance=voltage divided by current
//display the result on outcome on their assigned controls
let material=materialtextbox.Text
let current=Convert.ToDouble(currenttextbox.Text)
let voltage=Convert.ToDouble(voltstextbox.Text)
let resistance=voltage/current
materiallabel.Text<-material
resistancelabel.Text<-Convert.ToString(resistance))
 //when the exit button is clicked, close the form            
exitbutton.Click.Add(fun exit -> resistanceform.Close())  
Application.Run(resistanceform)

Visual F# 100 Examples: Example Number 2

Last time I have shared to you our first simple example of window forms application using Visual F#, let’s now proceed to our second example:

Problem: Make a windows forms application that will ask the amount of consumption, amount of investment, government spending, amount of exports and imports and display the net emports and Gross Domestic Product (GDP).

Solution:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. //creates our controls  
10. let gdpform=new Form(Text="Compute GDP", Size=new System.Drawing.Size(300, 330),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. let n1label=new Label(Text="Consumption:",Location=new System.Drawing.Point(0,20),AutoSize=true)  
12. let firsttextbox=new TextBox(Location=new System.Drawing.Point(80, 20))  
13. let n2label=new Label(Text="Investment:", Location=new System.Drawing.Point(0,50),AutoSize=true)  
14. let secondtextbox=new TextBox(Location=new System.Drawing.Point(80,50))  
15. let n3label=new Label(Text="Government spending:", Location=new System.Drawing.Point(0, 90),AutoSize=true)  
16. let thirdtextbox=new TextBox(Location=new System.Drawing.Point(130, 90))  
17. let n4label=new Label(Text="Exports:", Location=new System.Drawing.Point(0, 120),AutoSize=true)  
18. let fourthtextbox=new TextBox(Location=new System.Drawing.Point(130, 120))  
19. let n5label=new Label(Text="Imports:", Location=new System.Drawing.Point(0, 150),AutoSize=true)  
20. let fifthtextbox=new TextBox(Location=new System.Drawing.Point(130, 150))  
21. let n6label=new Label(Text="Imports:", Location=new System.Drawing.Point(0, 180),AutoSize=true)  
22. let netemlabel=new Label(Location=new System.Drawing.Point(130, 180),BorderStyle=BorderStyle.FixedSingle)  
23. let n7label=new Label(Text="GDP:", Location=new System.Drawing.Point(0, 210),AutoSize=true)  
24. let gdplabel=new Label(Location=new System.Drawing.Point(130, 210),BorderStyle=BorderStyle.FixedSingle)  
25. let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 250))  
26. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 250))  
27. //add the controls into the form  
28. gdpform.Controls.Add(n1label)  
29. gdpform.Controls.Add(firsttextbox)  
30. gdpform.Controls.Add(n2label)  
31. gdpform.Controls.Add(secondtextbox)  
32. gdpform.Controls.Add(n3label)  
33. gdpform.Controls.Add(thirdtextbox)  
34. gdpform.Controls.Add(n4label)  
35. gdpform.Controls.Add(fourthtextbox)  
36. gdpform.Controls.Add(n5label)  
37. gdpform.Controls.Add(fifthtextbox)  
38. gdpform.Controls.Add(n6label)  
39. gdpform.Controls.Add(netemlabel)  
40. gdpform.Controls.Add(n7label)  
41. gdpform.Controls.Add(gdplabel)  
42. gdpform.Controls.Add(computebutton)  
43. gdpform.Controls.Add(exitbutton)  
44. //when the compute button is clicked  
45. computebutton.Click.Add(fun compute->  
46. //assigned the numbers inputted to each textbox to their corresponding variable  
47. //compute the net emport using the formula net emport=export-import  
48. //compute the gdp using the formula gdp=consumption+investment+govspending+netemport  
49. let consumption=Convert.ToDouble(firsttextbox.Text)  
50. let investment=Convert.ToDouble(secondtextbox.Text)  
51. let govspending=Convert.ToDouble(thirdtextbox.Text)  
52. let export=Convert.ToDouble(fourthtextbox.Text)  
53. let import=Convert.ToDouble(fifthtextbox.Text)  
54. let netemport=export-import  
55. let gdp=(consumption+investment+govspending+netemport)  
56. netemlabel.Text<-Convert.ToString(netemport)  
57.                  gdplabel.Text<-Convert.ToString(gdp))  
58.  //when the exit button is clicked, close the form              
59. exitbutton.Click.Add(fun exit -> gdpform.Close())    
60. Application.Run(gdpform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
//creates our controls
let gdpform=new Form(Text="Compute GDP", Size=new System.Drawing.Size(300, 330),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
let n1label=new Label(Text="Consumption:",Location=new System.Drawing.Point(0,20),AutoSize=true)
let firsttextbox=new TextBox(Location=new System.Drawing.Point(80, 20))
let n2label=new Label(Text="Investment:", Location=new System.Drawing.Point(0,50),AutoSize=true)
let secondtextbox=new TextBox(Location=new System.Drawing.Point(80,50))
let n3label=new Label(Text="Government spending:", Location=new System.Drawing.Point(0, 90),AutoSize=true)
let thirdtextbox=new TextBox(Location=new System.Drawing.Point(130, 90))
let n4label=new Label(Text="Exports:", Location=new System.Drawing.Point(0, 120),AutoSize=true)
let fourthtextbox=new TextBox(Location=new System.Drawing.Point(130, 120))
let n5label=new Label(Text="Imports:", Location=new System.Drawing.Point(0, 150),AutoSize=true)
let fifthtextbox=new TextBox(Location=new System.Drawing.Point(130, 150))
let n6label=new Label(Text="Imports:", Location=new System.Drawing.Point(0, 180),AutoSize=true)
let netemlabel=new Label(Location=new System.Drawing.Point(130, 180),BorderStyle=BorderStyle.FixedSingle)
let n7label=new Label(Text="GDP:", Location=new System.Drawing.Point(0, 210),AutoSize=true)
let gdplabel=new Label(Location=new System.Drawing.Point(130, 210),BorderStyle=BorderStyle.FixedSingle)
let computebutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 250))
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 250))
//add the controls into the form
gdpform.Controls.Add(n1label)
gdpform.Controls.Add(firsttextbox)
gdpform.Controls.Add(n2label)
gdpform.Controls.Add(secondtextbox)
gdpform.Controls.Add(n3label)
gdpform.Controls.Add(thirdtextbox)
gdpform.Controls.Add(n4label)
gdpform.Controls.Add(fourthtextbox)
gdpform.Controls.Add(n5label)
gdpform.Controls.Add(fifthtextbox)
gdpform.Controls.Add(n6label)
gdpform.Controls.Add(netemlabel)
gdpform.Controls.Add(n7label)
gdpform.Controls.Add(gdplabel)
gdpform.Controls.Add(computebutton)
gdpform.Controls.Add(exitbutton)
//when the compute button is clicked
computebutton.Click.Add(fun compute->
//assigned the numbers inputted to each textbox to their corresponding variable
//compute the net emport using the formula net emport=export-import
//compute the gdp using the formula gdp=consumption+investment+govspending+netemport
let consumption=Convert.ToDouble(firsttextbox.Text)
let investment=Convert.ToDouble(secondtextbox.Text)
let govspending=Convert.ToDouble(thirdtextbox.Text)
let export=Convert.ToDouble(fourthtextbox.Text)
let import=Convert.ToDouble(fifthtextbox.Text)
let netemport=export-import
let gdp=(consumption+investment+govspending+netemport)
netemlabel.Text<-Convert.ToString(netemport)
                 gdplabel.Text<-Convert.ToString(gdp))
 //when the exit button is clicked, close the form            
exitbutton.Click.Add(fun exit -> gdpform.Close())  
Application.Run(gdpform)

Visual F# 100 Examples: Example Number 1

Starting today, I will be sharing to you guys some learning examples that will aid you in learning windows forms application programming in Visual F#. Our target is to be able to share at least 100 examples. Let’s start with example number 1:

Problem: Make a windows form application that will ask the user’s mental age and chronological age and display his intelligence quotient (IQ).

Solution:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. //creates a new form  
10. let iqform=new Form(Text="Compute IQ", Size=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. //creates a label  
12. let n1label=new Label(Text="Mental age:",Top=20,Left=5,AutoSize=true)  
13. let firsttextbox=new TextBox(Location=new System.Drawing.Point(80, 20))  
14. //creates another label and change its text to “Second number:”  
15. let n2label=new Label(Text="Chronological age:", Location=new System.Drawing.Point(0,50),AutoSize=true)  
16. let secondtextbox=new TextBox(Location=new System.Drawing.Point(100,50))  
17. //creates another label and change its text to sum  
18. let n3label=new Label(Text="IQ:", Location=new System.Drawing.Point(0, 90),AutoSize=true)  
19. //creates a label that will display the result of the computation  
20. let anslabel=new Label(Location=new System.Drawing.Point(80, 90), BorderStyle=BorderStyle.FixedSingle)  
21. //make our buttons  
22. let addbutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 130))  
23. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 130))  
24. //add the controls into the form  
25. iqform.Controls.Add(n1label)  
26. iqform.Controls.Add(firsttextbox)  
27. iqform.Controls.Add(n2label)  
28. iqform.Controls.Add(secondtextbox)  
29. iqform.Controls.Add(n3label)  
30. iqform.Controls.Add(anslabel)  
31. iqform.Controls.Add(addbutton)  
32. iqform.Controls.Add(exitbutton)  
33.   
34. //when the compute button is clicked  
35. addbutton.Click.Add(fun addfunction ->  
36. let manum=Convert.ToDouble(firsttextbox.Text)  
37. let canum=Convert.ToDouble(secondtextbox.Text)  
38. let iq=Convert.ToDouble((manum/canum)*100.00)  
39.   
40. //display the iq value in the anslabel  
41. anslabel.Text<-Convert.ToString(iq))  
42.  //when the exit button is clicked, close the form              
43. exitbutton.Click.Add(fun exit -> iqform.Close())    
44. Application.Run(iqform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
//creates a new form
let iqform=new Form(Text="Compute IQ", Size=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
//creates a label
let n1label=new Label(Text="Mental age:",Top=20,Left=5,AutoSize=true)
let firsttextbox=new TextBox(Location=new System.Drawing.Point(80, 20))
//creates another label and change its text to “Second number:”
let n2label=new Label(Text="Chronological age:", Location=new System.Drawing.Point(0,50),AutoSize=true)
let secondtextbox=new TextBox(Location=new System.Drawing.Point(100,50))
//creates another label and change its text to sum
let n3label=new Label(Text="IQ:", Location=new System.Drawing.Point(0, 90),AutoSize=true)
//creates a label that will display the result of the computation
let anslabel=new Label(Location=new System.Drawing.Point(80, 90), BorderStyle=BorderStyle.FixedSingle)
//make our buttons
let addbutton=new Button(Text="Compute", Location=new System.Drawing.Point(100, 130))
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 130))
//add the controls into the form
iqform.Controls.Add(n1label)
iqform.Controls.Add(firsttextbox)
iqform.Controls.Add(n2label)
iqform.Controls.Add(secondtextbox)
iqform.Controls.Add(n3label)
iqform.Controls.Add(anslabel)
iqform.Controls.Add(addbutton)
iqform.Controls.Add(exitbutton)

//when the compute button is clicked
addbutton.Click.Add(fun addfunction ->
let manum=Convert.ToDouble(firsttextbox.Text)
let canum=Convert.ToDouble(secondtextbox.Text)
let iq=Convert.ToDouble((manum/canum)*100.00)

//display the iq value in the anslabel
anslabel.Text<-Convert.ToString(iq))
 //when the exit button is clicked, close the form            
exitbutton.Click.Add(fun exit -> iqform.Close())  
Application.Run(iqform)

Simplest input validation using Char.IsNumber and Char.IsLetter

The following example demonstrates how to validate a user input by using the Char.IsNumber and Char.IsLetter character manipulation functions:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. //creates a font  
10. let ffont=new Font("Verdana", 9.75F,FontStyle.Regular, GraphicsUnit.Point)    
11. let validateform = new Form(Text="Validate Inputs",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen)  
12. //creates our controls  
13. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 170))    
14. let okbutton=new Button(Text="Ok", Location=new System.Drawing.Point(100, 170))   
15. let label1=new Label(Text="Enter a name:",Location=new System.Drawing.Point(0, 10),AutoSize=true)  
16. let nametxtbox=new TextBox(Location=new System.Drawing.Point(120,10),BorderStyle=BorderStyle.FixedSingle)  
17. validateform.Font<-ffont  
18. //adds the controls to our form  
19. validateform.Controls.Add(exitbutton)  
20. validateform.Controls.Add(okbutton)  
21. validateform.Controls.Add(label1)  
22. validateform.Controls.Add(nametxtbox)  
23. //when the oK button is clicked  
24. okbutton.Click.Add(fun ok->  
25. //if the input begins with a letter then  
26. if (Char.IsLetter(Convert.ToChar(nametxtbox.Text.Chars(0)))) then  
27. //prompt that its a valid name  
28. MessageBox.Show("The name you entered is valid ", "Validate Inputs",MessageBoxButtons.OK, MessageBoxIcon.Information)|>ignore  
29. //if the input begins with a number then                           
30. if (Char.IsNumber(Convert.ToChar(nametxtbox.Text.Chars(0)))) then  
31. //prompt that its an invalid name  
32. MessageBox.Show("You must enter a valid name", "Validate Inputs",MessageBoxButtons.OK, MessageBoxIcon.Information)|>ignore)  
33. //when the exit button is clicked  
34. exitbutton.Click.Add(fun exit->validateform.Close())  
35. //executes our application  
36. Application.Run(validateform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
//creates a font
let ffont=new Font("Verdana", 9.75F,FontStyle.Regular, GraphicsUnit.Point)  
let validateform = new Form(Text="Validate Inputs",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen)
//creates our controls
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 170))  
let okbutton=new Button(Text="Ok", Location=new System.Drawing.Point(100, 170)) 
let label1=new Label(Text="Enter a name:",Location=new System.Drawing.Point(0, 10),AutoSize=true)
let nametxtbox=new TextBox(Location=new System.Drawing.Point(120,10),BorderStyle=BorderStyle.FixedSingle)
validateform.Font<-ffont
//adds the controls to our form
validateform.Controls.Add(exitbutton)
validateform.Controls.Add(okbutton)
validateform.Controls.Add(label1)
validateform.Controls.Add(nametxtbox)
//when the oK button is clicked
okbutton.Click.Add(fun ok->
//if the input begins with a letter then
if (Char.IsLetter(Convert.ToChar(nametxtbox.Text.Chars(0)))) then
//prompt that its a valid name
MessageBox.Show("The name you entered is valid ", "Validate Inputs",MessageBoxButtons.OK, MessageBoxIcon.Information)|>ignore
//if the input begins with a number then                         
if (Char.IsNumber(Convert.ToChar(nametxtbox.Text.Chars(0)))) then
//prompt that its an invalid name
MessageBox.Show("You must enter a valid name", "Validate Inputs",MessageBoxButtons.OK, MessageBoxIcon.Information)|>ignore)
//when the exit button is clicked
exitbutton.Click.Add(fun exit->validateform.Close())
//executes our application
Application.Run(validateform)

Click the run icon when done entering these codes in Visual F# code editor window. Try entering any number in the name text box and clicking the ok button. You should see an output similar to the following:

Paint Application in Visual F#

The following example demonstrates how to make a simple Paint-like application in Visual F#:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. open System.Drawing.Drawing2D  
10. let drawingform = new Form(Text="Draw Objects",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
11. //creates our control  
12. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
13. let erasebutton=new Button(Text="Erase", Location=new System.Drawing.Point(120, 200))  
14. let colorbutton=new Button(Text="Brush Color", Location=new System.Drawing.Point(40, 200))  
15. drawingform.Controls.Add(exitbutton)  
16. drawingform.Controls.Add(erasebutton)  
17. drawingform.Controls.Add(colorbutton)  
18. //creates a color dialog box  
19. let colordlg=new ColorDialog()  
20. //creates a colorblend object  
21. let mutable color=new ColorBlend()  
22.   
23. let gr=drawingform.CreateGraphics()  
24. gr.SmoothingMode<-SmoothingMode.HighQuality  
25. //when the form is loaded, change its color to white  
26. drawingform.Load.Add(fun background->  
27. //set the default brush color to indigo  
28. color.Colors<-[|Color.Indigo|]  
29.                         drawingform.BackColor<-Color.White)  
30.   
31. drawingform.MouseMove.Add(fun trail->  
32. //when the mouse button is moved and the left button is clicked  
33.   
34. if (trail.Button=System.Windows.Forms.MouseButtons.Left)then  
35. //draw the object assign the color seleted from the color dialog as a brush color  
36. gr.FillRectangle(new SolidBrush(color.Colors.[0]),new Rectangle(trail.X,trail.Y,5,5)))   
37. //when the erase button is clicked  
38. //erase the object drawn in the form  
39. erasebutton.Click.Add(fun erase->gr.Clear(Color.White))   
40. //when the exit button is clicked  
41. //quit the form                                                                                                                
42. exitbutton.Click.Add(fun quit->drawingform.Close())  
43. //when the brush color button is selected                                                            
44. colorbutton.Click.Add(fun colors->  
45. //display the Color Dialog box  
46. if colordlg.ShowDialog()=DialogResult.OK then  
47. //store the value selected by the user in our colorblend object  
48. color.Colors<-[|colordlg.Color|])  
49. //executes our application  
50. Application.Run(drawingform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
open System.Drawing.Drawing2D
let drawingform = new Form(Text="Draw Objects",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let erasebutton=new Button(Text="Erase", Location=new System.Drawing.Point(120, 200))
let colorbutton=new Button(Text="Brush Color", Location=new System.Drawing.Point(40, 200))
drawingform.Controls.Add(exitbutton)
drawingform.Controls.Add(erasebutton)
drawingform.Controls.Add(colorbutton)
//creates a color dialog box
let colordlg=new ColorDialog()
//creates a colorblend object
let mutable color=new ColorBlend()

let gr=drawingform.CreateGraphics()
gr.SmoothingMode<-SmoothingMode.HighQuality
//when the form is loaded, change its color to white
drawingform.Load.Add(fun background->
//set the default brush color to indigo
color.Colors<-[|Color.Indigo|]
                        drawingform.BackColor<-Color.White)

drawingform.MouseMove.Add(fun trail->
//when the mouse button is moved and the left button is clicked

if (trail.Button=System.Windows.Forms.MouseButtons.Left)then
//draw the object assign the color seleted from the color dialog as a brush color
gr.FillRectangle(new SolidBrush(color.Colors.[0]),new Rectangle(trail.X,trail.Y,5,5))) 
//when the erase button is clicked
//erase the object drawn in the form
erasebutton.Click.Add(fun erase->gr.Clear(Color.White)) 
//when the exit button is clicked
//quit the form                                                                                                              
exitbutton.Click.Add(fun quit->drawingform.Close())
//when the brush color button is selected                                                          
colorbutton.Click.Add(fun colors->
//display the Color Dialog box
if colordlg.ShowDialog()=DialogResult.OK then
//store the value selected by the user in our colorblend object
color.Colors<-[|colordlg.Color|])
//executes our application
Application.Run(drawingform)

Click the run icon once you are done entering these codes in the code editor window. You should see the following outputs:

Mouse Trails using Basic shapes

Obsessed with mouse trails? Try the following sample applications:
1. Line Mouse Trail
Code:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let gr=trailform.CreateGraphics()  
13. trailform.Controls.Add(exitbutton)  
14. trailform.MouseMove.Add(fun trail->gr.DrawLine(Pens.Peru,trail.X,trail.Y,trail.X+1,trail.Y+1))                                                                                                                  
15. exitbutton.Click.Add(fun quit->trailform.Close())                                                            
16. //executes our application  
17. Application.Run(trailform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let gr=trailform.CreateGraphics()
trailform.Controls.Add(exitbutton)
trailform.MouseMove.Add(fun trail->gr.DrawLine(Pens.Peru,trail.X,trail.Y,trail.X+1,trail.Y+1))                                                                                                                
exitbutton.Click.Add(fun quit->trailform.Close())                                                          
//executes our application
Application.Run(trailform)

Output:

2. Circle Mouse Trail
Code:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let gr=trailform.CreateGraphics()  
13. trailform.Controls.Add(exitbutton)  
14. trailform.MouseMove.Add(fun trail->gr.DrawEllipse(Pens.IndianRed,new Rectangle(trail.X,trail.Y,10,10)))                                                                                                                      
15. exitbutton.Click.Add(fun quit->trailform.Close())                                                            
16. //executes our application  
17. Application.Run(trailform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let gr=trailform.CreateGraphics()
trailform.Controls.Add(exitbutton)
trailform.MouseMove.Add(fun trail->gr.DrawEllipse(Pens.IndianRed,new Rectangle(trail.X,trail.Y,10,10)))                                                                                                                    
exitbutton.Click.Add(fun quit->trailform.Close())                                                          
//executes our application
Application.Run(trailform)

Output:

3. Rectangle Mouse Trail
Code:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let gr=trailform.CreateGraphics()  
13. trailform.Controls.Add(exitbutton)  
14. trailform.MouseMove.Add(fun trail->gr.DrawRectangle(Pens.Fuchsia,new Rectangle(trail.X,trail.Y,5,5)))                                                                                                                      
15. exitbutton.Click.Add(fun quit->trailform.Close())                                                            
16. //executes our application  
17. Application.Run(trailform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let gr=trailform.CreateGraphics()
trailform.Controls.Add(exitbutton)
trailform.MouseMove.Add(fun trail->gr.DrawRectangle(Pens.Fuchsia,new Rectangle(trail.X,trail.Y,5,5)))                                                                                                                    
exitbutton.Click.Add(fun quit->trailform.Close())                                                          
//executes our application
Application.Run(trailform)

Output:

4. Arc Mouse Trail
Code:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let gr=trailform.CreateGraphics()  
13. trailform.Controls.Add(exitbutton)  
14. trailform.MouseMove.Add(fun trail->gr.DrawArc(Pens.Violet,new Rectangle(trail.X,trail.Y,5,5),180.0f,-180.0f))                                                                                                                 
15. exitbutton.Click.Add(fun quit->trailform.Close())                                                            
16. //executes our application  
17. Application.Run(trailform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let gr=trailform.CreateGraphics()
trailform.Controls.Add(exitbutton)
trailform.MouseMove.Add(fun trail->gr.DrawArc(Pens.Violet,new Rectangle(trail.X,trail.Y,5,5),180.0f,-180.0f))                                                                                                               
exitbutton.Click.Add(fun quit->trailform.Close())                                                          
//executes our application
Application.Run(trailform)

Output:

5. Filled-Arc/FillPie Mouse Trail
Code:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let gr=trailform.CreateGraphics()  
13. trailform.Controls.Add(exitbutton)  
14. trailform.MouseMove.Add(fun trail->gr.FillPie(Brushes.MidnightBlue,new Rectangle(trail.X,trail.Y,10,10),180.0f,180.0f))                                                                                                                 
15. exitbutton.Click.Add(fun quit->trailform.Close())                                                            
16. //executes our application  
17. Application.Run(trailform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let gr=trailform.CreateGraphics()
trailform.Controls.Add(exitbutton)
trailform.MouseMove.Add(fun trail->gr.FillPie(Brushes.MidnightBlue,new Rectangle(trail.X,trail.Y,10,10),180.0f,180.0f))                                                                                                               
exitbutton.Click.Add(fun quit->trailform.Close())                                                          
//executes our application
Application.Run(trailform)

Output:

6. Filled Circle Mouse Trail
Code:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let gr=trailform.CreateGraphics()  
13. trailform.Controls.Add(exitbutton)  
14. trailform.MouseMove.Add(fun trail->gr.FillEllipse(Brushes.Tomato,new Rectangle(trail.X,trail.Y,10,10)))                                                                                                                 
15. exitbutton.Click.Add(fun quit->trailform.Close())                                                            
16. //executes our application  
17. Application.Run(trailform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let gr=trailform.CreateGraphics()
trailform.Controls.Add(exitbutton)
trailform.MouseMove.Add(fun trail->gr.FillEllipse(Brushes.Tomato,new Rectangle(trail.X,trail.Y,10,10)))                                                                                                               
exitbutton.Click.Add(fun quit->trailform.Close())                                                          
//executes our application
Application.Run(trailform)

Output:

7. Filled Rectangle Mouse Trail
Code:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let gr=trailform.CreateGraphics()  
13. trailform.Controls.Add(exitbutton)  
14. trailform.MouseMove.Add(fun trail->gr.FillRectangle(Brushes.Indigo,new Rectangle(trail.X,trail.Y,20,20)))                                                                                                                 
15. exitbutton.Click.Add(fun quit->trailform.Close())                                                            
16. //executes our application  
17. Application.Run(trailform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let trailform = new Form(Text="Display Mouse Trail",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let gr=trailform.CreateGraphics()
trailform.Controls.Add(exitbutton)
trailform.MouseMove.Add(fun trail->gr.FillRectangle(Brushes.Indigo,new Rectangle(trail.X,trail.Y,20,20)))                                                                                                               
exitbutton.Click.Add(fun quit->trailform.Close())                                                          
//executes our application
Application.Run(trailform)

Output:

Creating a Customized Mouse Pointer

Aside from using pre-defined mouse pointers such as Cursors.Arrow and Cursors.Cross, you can also use customized mouse pointers in Visual F#. Follow these steps for a simple example:

1. Download a cursor creator software such as Axialis CursorWorkShop or Icon Craft.

2. Create a .cur file and name it “pointer.cur”.

3. Start Visual F#>Create a new Project.

4. Enter the following codes:

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. let mouseform = new Form(Text="Cutom Mouse Pointer",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
10. //creates our control  
11. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
12. let customcur=new System.Windows.Forms.Cursor("pointer.cur")  
13. mouseform.MouseHover.Add(fun cutom->mouseform.Cursor<-customcur)   
14. mouseform.Controls.Add(exitbutton)                                                                                                  
15. exitbutton.Click.Add(fun quit->mouseform.Close())                                                            
16. //executes our application  
17. Application.Run(mouseform)  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let mouseform = new Form(Text="Cutom Mouse Pointer",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let customcur=new System.Windows.Forms.Cursor("pointer.cur")
mouseform.MouseHover.Add(fun cutom->mouseform.Cursor<-customcur) 
mouseform.Controls.Add(exitbutton)                                                                                                
exitbutton.Click.Add(fun quit->mouseform.Close())                                                          
//executes our application
Application.Run(mouseform)

5. Click the Open Folder>bin>debug> then copy and paste pointer.cur.

6. Run your application

Printing an Image Data

To print an image or text, use a PrintDocument control. To following example shows how to print an image data, using a PrintDocument control.

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1. // Learn more about F# at http://fsharp.net  
2. //specifies the memory location of the class files  
3. //that will be needed in our application  
4. open System.Collections.Generic  
5. open System  
6. open System.Windows.Forms  
7. open System.ComponentModel  
8. open System.Drawing  
9. open System.Drawing.Printing  
10.   
11. open System.Drawing.Imaging  
12. let imageform = new Form(Text="Print Form",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
13. //creates our control  
14. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))  
15. let loadbutton=new Button(Text="Load", Location=new System.Drawing.Point(120, 200))  
16. let prnbutton=new Button(Text="Print", Location=new System.Drawing.Point(40, 200))  
17. let pic=new PictureBox(SizeMode=PictureBoxSizeMode.StretchImage,Location=new System.Drawing.Point(20, 20),BorderStyle=BorderStyle.FixedSingle,Size=new System.Drawing.Size(100, 100))  
18. let label=new Label(AutoSize=true,Location=new System.Drawing.Point(0, 120))  
19. let dlg=new OpenFileDialog()  
20. let gr=imageform.CreateGraphics()  
21. let prn=new System.Drawing.Printing.PrintDocument()  
22. imageform .Controls.Add(pic)  
23. imageform.Controls.Add(loadbutton)  
24. imageform.Controls.Add(label)  
25. imageform.Controls.Add(prnbutton)  
26. imageform.Controls.Add(exitbutton)  
27. //sends the data to the printer  
28. prnbutton.Click.Add(fun startprint->prn.Print())  
29.   
30. loadbutton.Click.Add(fun load->  
31. //filter dialog result  
32. dlg.Filter <- "JPEG Images (*.jpg,*.jpeg)|*.jpg;*.jpeg|Gif Images (*.gif)|*.gif"  
33. //adds title to your dialog box  
34.                    dlg.Title<-"Select an Image File"  
35.                    if dlg.ShowDialog()=DialogResult.OK then  
36. //creates a bitmap object  
37. //assigns the image selected by the user as its value  
38.                       let bmp=new System.Drawing.Bitmap(dlg.FileName)  
39.                       bmp.RotateFlip(RotateFlipType.RotateNoneFlipNone)  
40. //assigns the loaded image as a picturebox value  
41.                       pic.Image<-bmp  
42. //displays the image url in our label  
43.                       label.Text<-"\t\tFilename:" + Convert.ToString(Convert.ToChar(32))+ (dlg.FileName))   
44. //specifies the data to be printed  
45. //in this case our image                        
46. prn.PrintPage.Add(fun printdata->gr.DrawImage(pic.Image,10,10))  
47. //close the form                                                                                                          
48. exitbutton.Click.Add(fun quit->imageform.Close())                                           
49. [<stathread>]                      
50. //executes our application  
51. Application.Run(imageform)  
52. </stathread>  

// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
open System.Drawing.Printing

open System.Drawing.Imaging
let imageform = new Form(Text="Print Form",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 200))
let loadbutton=new Button(Text="Load", Location=new System.Drawing.Point(120, 200))
let prnbutton=new Button(Text="Print", Location=new System.Drawing.Point(40, 200))
let pic=new PictureBox(SizeMode=PictureBoxSizeMode.StretchImage,Location=new System.Drawing.Point(20, 20),BorderStyle=BorderStyle.FixedSingle,Size=new System.Drawing.Size(100, 100))
let label=new Label(AutoSize=true,Location=new System.Drawing.Point(0, 120))
let dlg=new OpenFileDialog()
let gr=imageform.CreateGraphics()
let prn=new System.Drawing.Printing.PrintDocument()
imageform .Controls.Add(pic)
imageform.Controls.Add(loadbutton)
imageform.Controls.Add(label)
imageform.Controls.Add(prnbutton)
imageform.Controls.Add(exitbutton)
//sends the data to the printer
prnbutton.Click.Add(fun startprint->prn.Print())

loadbutton.Click.Add(fun load->
//filter dialog result
dlg.Filter <- "JPEG Images (*.jpg,*.jpeg)|*.jpg;*.jpeg|Gif Images (*.gif)|*.gif"
//adds title to your dialog box
                   dlg.Title<-"Select an Image File"
                   if dlg.ShowDialog()=DialogResult.OK then
//creates a bitmap object
//assigns the image selected by the user as its value
                      let bmp=new System.Drawing.Bitmap(dlg.FileName)
                      bmp.RotateFlip(RotateFlipType.RotateNoneFlipNone)
//assigns the loaded image as a picturebox value
                      pic.Image<-bmp
//displays the image url in our label
                      label.Text<-"\t\tFilename:" + Convert.ToString(Convert.ToChar(32))+ (dlg.FileName)) 
//specifies the data to be printed
//in this case our image                      
prn.PrintPage.Add(fun printdata->gr.DrawImage(pic.Image,10,10))
//close the form                                                                                                        
exitbutton.Click.Add(fun quit->imageform.Close())                                         
[]                    
//executes our application
Application.Run(imageform)

Drawing Triangles and Circles

To draw a triangle, use the DrawLine or DrawPolygon method. Here’s an example that uses DrawPolygon method:

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1. // Learn more about F# at http://fsharp.net  
2. // Learn more about F# at http://fsharp.net  
3. //specifies the memory location of the class files  
4. //that will be needed in our application  
5. open System.Collections.Generic  
6. open System  
7. open System.Windows.Forms  
8. open System.ComponentModel  
9. open System.Drawing  
10. let graphicform = new Form(Text="Draw Triangle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
11. //creates our control  
12. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))  
13. graphicform.Paint.Add(fun draw->  
14. let array=[|new Point(0,150);new Point(150,10);new Point(300,150)|]  
15. let pen=new Pen(Color.Blue,Width=12.0f)  
16. draw.Graphics.DrawPolygon(pen,array))  
17. graphicform.Controls.Add(exitbutton)  
18. //executes our application  
19. Application.Run(graphicform)  

// Learn more about F# at http://fsharp.net
// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let graphicform = new Form(Text="Draw Triangle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))
graphicform.Paint.Add(fun draw->
let array=[|new Point(0,150);new Point(150,10);new Point(300,150)|]
let pen=new Pen(Color.Blue,Width=12.0f)
draw.Graphics.DrawPolygon(pen,array))
graphicform.Controls.Add(exitbutton)
//executes our application
Application.Run(graphicform)

To draw a filled triangle, use the FillPolygon method:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. // Learn more about F# at http://fsharp.net  
3. //specifies the memory location of the class files  
4. //that will be needed in our application  
5. open System.Collections.Generic  
6. open System  
7. open System.Windows.Forms  
8. open System.ComponentModel  
9. open System.Drawing  
10. let graphicform = new Form(Text="Draw Triangle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
11. //creates our control  
12. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))  
13. graphicform.Paint.Add(fun draw->  
14. let array=[|new Point(0,150);new Point(150,10);new Point(300,150)|]  
15. let brush=new SolidBrush(Color.Blue)  
16. draw.Graphics.FillPolygon(brush,array))  
17. graphicform.Controls.Add(exitbutton)  
18. //executes our application  
19. Application.Run(graphicform)  

// Learn more about F# at http://fsharp.net
// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let graphicform = new Form(Text="Draw Triangle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))
graphicform.Paint.Add(fun draw->
let array=[|new Point(0,150);new Point(150,10);new Point(300,150)|]
let brush=new SolidBrush(Color.Blue)
draw.Graphics.FillPolygon(brush,array))
graphicform.Controls.Add(exitbutton)
//executes our application
Application.Run(graphicform)

To draw a circle, use the DrawEllipse method:

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1. // Learn more about F# at http://fsharp.net  
2. // Learn more about F# at http://fsharp.net  
3. //specifies the memory location of the class files  
4. //that will be needed in our application  
5. open System.Collections.Generic  
6. open System  
7. open System.Windows.Forms  
8. open System.ComponentModel  
9. open System.Drawing  
10. let graphicform = new Form(Text="Draw Circle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
11. //creates our control  
12. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))  
13. graphicform.Paint.Add(fun draw->  
14.   
15. let pen=new Pen(Color.Blue,Width=12.0f)  
16. draw.Graphics.DrawEllipse(pen,0.0f,0.0f,100.0f,100.0f))  
17.   
18. graphicform.Controls.Add(exitbutton)  
19. //executes our application  
20. Application.Run(graphicform)  

// Learn more about F# at http://fsharp.net
// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let graphicform = new Form(Text="Draw Circle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))
graphicform.Paint.Add(fun draw->

let pen=new Pen(Color.Blue,Width=12.0f)
draw.Graphics.DrawEllipse(pen,0.0f,0.0f,100.0f,100.0f))

graphicform.Controls.Add(exitbutton)
//executes our application
Application.Run(graphicform)

To draw a solid circle, use the FillEllipse method:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. // Learn more about F# at http://fsharp.net  
3. //specifies the memory location of the class files  
4. //that will be needed in our application  
5. open System.Collections.Generic  
6. open System  
7. open System.Windows.Forms  
8. open System.ComponentModel  
9. open System.Drawing  
10. let graphicform = new Form(Text="Draw Circle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)  
11. //creates our control  
12. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))  
13. graphicform.Paint.Add(fun draw->  
14.   
15. let brush=new SolidBrush(Color.Blue)  
16. draw.Graphics.FillEllipse(brush,0.0f,0.0f,100.0f,100.0f))  
17.   
18. graphicform.Controls.Add(exitbutton)  
19. //executes our application  
20. Application.Run(graphicform)  

// Learn more about F# at http://fsharp.net
// Learn more about F# at http://fsharp.net
//specifies the memory location of the class files
//that will be needed in our application
open System.Collections.Generic
open System
open System.Windows.Forms
open System.ComponentModel
open System.Drawing
let graphicform = new Form(Text="Draw Circle",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 250),StartPosition=FormStartPosition.CenterScreen)
//creates our control
let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 200))
graphicform.Paint.Add(fun draw->

let brush=new SolidBrush(Color.Blue)
draw.Graphics.FillEllipse(brush,0.0f,0.0f,100.0f,100.0f))

graphicform.Controls.Add(exitbutton)
//executes our application
Application.Run(graphicform)

Display the Date or Time from a DateTime Object

There are several ways on how to retrieve the date or time part from a datetime object, here are the few methods that I discover through research and experimentation:

1. Using Substring

Display the time part using Substring:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //use the F# library  
3. open System  
4. //use this to enable the intellisense. Very helpful in coding your application  
5. open System.Drawing   
6. //specify the location of the Form classes  
7. open System.Windows.Forms  
8. let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)  
9. //creates a form  
10. let timerform=new Form(Text="Display Time Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. let timelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)  
12.   
13. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)  
14. //create a timer object and set its interval to 1 second  
15. //by default timer are disabled so you'll need to enable it  
16. let timer1=new Timer(Interval=1000,Enabled=true)  
17. timelabel.Font<-ffont  
18. //change it every 1 min second  
19. timer1.Tick.Add(fun time->  
20. //assigns the current date and time to a variable  
21. let datetime=Convert.ToString(System.DateTime.Now)  
22. //retrieves the value of the datetime variable  
23. //starting from the 11th character  
24. let timepart=datetime.Substring(10)  
25. //display the time  
26. timelabel.Text<-timepart)  
27.                   
28. //adds the exit button to our form  
29. timerform.Controls.Add(timelabel)  
30. timerform.Controls.Add(exitbutton)  
31. //when the exit button is clicked  
32. exitbutton.Click.Add(fun quit->  
33. //stops the time  
34. timer1.Stop()  
35. //close the form  
36. timerform.Close())                     
37. //show our form  
38. timerform.Show()  
39. //execute our application  
40. Application.Run(timerform)  

// Learn more about F# at http://fsharp.net
//use the F# library
open System
//use this to enable the intellisense. Very helpful in coding your application
open System.Drawing 
//specify the location of the Form classes
open System.Windows.Forms
let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)
//creates a form
let timerform=new Form(Text="Display Time Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
let timelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)

let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)
//create a timer object and set its interval to 1 second
//by default timer are disabled so you'll need to enable it
let timer1=new Timer(Interval=1000,Enabled=true)
timelabel.Font<-ffont
//change it every 1 min second
timer1.Tick.Add(fun time->
//assigns the current date and time to a variable
let datetime=Convert.ToString(System.DateTime.Now)
//retrieves the value of the datetime variable
//starting from the 11th character
let timepart=datetime.Substring(10)
//display the time
timelabel.Text<-timepart)
                
//adds the exit button to our form
timerform.Controls.Add(timelabel)
timerform.Controls.Add(exitbutton)
//when the exit button is clicked
exitbutton.Click.Add(fun quit->
//stops the time
timer1.Stop()
//close the form
timerform.Close())                   
//show our form
timerform.Show()
//execute our application
Application.Run(timerform)

Display the time part using the substring function:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //use the F# library  
3. open System  
4. //use this to enable the intellisense. Very helpful in coding your application  
5. open System.Drawing   
6. //specify the location of the Form classes  
7. open System.Windows.Forms  
8. let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)  
9. //creates a form  
10. let dateform=new Form(Text="Display Date Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. //use the random function to generate random numbers  
12. let datelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)  
13.   
14. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)  
15.   
16. datelabel.Font<-ffont  
17. dateform.Load.Add(fun time->  
18. //assigns the current date and time to the datetime variable  
19. let datetime=Convert.ToString(System.DateTime.Now)  
20. //retrieves the text from the datetime variable staring from the first  
21. //character to the 11th character  
22. let datepart=datetime.Substring(0,10)  
23. //display the current time  
24. datelabel.Text<-datepart)  
25.                   
26. //adds the exit button to our form  
27. dateform.Controls.Add(datelabel)  
28. dateform.Controls.Add(exitbutton)  
29. //when the exit button is clicked  
30. exitbutton.Click.Add(fun quit->dateform.Close())                     
31. //execute our application  
32. Application.Run(dateform)  

// Learn more about F# at http://fsharp.net
//use the F# library
open System
//use this to enable the intellisense. Very helpful in coding your application
open System.Drawing 
//specify the location of the Form classes
open System.Windows.Forms
let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)
//creates a form
let dateform=new Form(Text="Display Date Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
//use the random function to generate random numbers
let datelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)

let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)

datelabel.Font<-ffont
dateform.Load.Add(fun time->
//assigns the current date and time to the datetime variable
let datetime=Convert.ToString(System.DateTime.Now)
//retrieves the text from the datetime variable staring from the first
//character to the 11th character
let datepart=datetime.Substring(0,10)
//display the current time
datelabel.Text<-datepart)
                
//adds the exit button to our form
dateform.Controls.Add(datelabel)
dateform.Controls.Add(exitbutton)
//when the exit button is clicked
exitbutton.Click.Add(fun quit->dateform.Close())                   
//execute our application
Application.Run(dateform)

2. Using Remove

Display the time part using Remove:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //use the F# library  
3. open System  
4. //use this to enable the intellisense. Very helpful in coding your application  
5. open System.Drawing   
6. //specify the location of the Form classes  
7. open System.Windows.Forms  
8. let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)  
9. //creates a form  
10. let timerform=new Form(Text="Display Time Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. let timelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)  
12.   
13. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)  
14. //create a timer object and set its interval to 1 second  
15. //by default timer are disabled so you'll need to enable it  
16. let timer1=new Timer(Interval=1000,Enabled=true)  
17. timelabel.Font<-ffont  
18. //change it every 1 min second  
19. timer1.Tick.Add(fun time->  
20. //assigns the current date and time to the datetime variable  
21. let datetime=Convert.ToString(System.DateTime.Now)  
22. //removes the first 11 characters from the datetime variable  
23. let timepart=datetime.Remove(0,10)  
24. //display the current time  
25. timelabel.Text<-timepart)  
26.                   
27. //adds the exit button to our form  
28. timerform.Controls.Add(timelabel)  
29. timerform.Controls.Add(exitbutton)  
30. //when the exit button is clicked  
31. exitbutton.Click.Add(fun quit->  
32. //stops the time  
33. timer1.Stop()  
34. //close the form  
35. timerform.Close())                     
36. //show our form  
37. timerform.Show()  
38. //execute our application  
39. Application.Run(timerform)  

// Learn more about F# at http://fsharp.net
//use the F# library
open System
//use this to enable the intellisense. Very helpful in coding your application
open System.Drawing 
//specify the location of the Form classes
open System.Windows.Forms
let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)
//creates a form
let timerform=new Form(Text="Display Time Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
let timelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)

let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)
//create a timer object and set its interval to 1 second
//by default timer are disabled so you'll need to enable it
let timer1=new Timer(Interval=1000,Enabled=true)
timelabel.Font<-ffont
//change it every 1 min second
timer1.Tick.Add(fun time->
//assigns the current date and time to the datetime variable
let datetime=Convert.ToString(System.DateTime.Now)
//removes the first 11 characters from the datetime variable
let timepart=datetime.Remove(0,10)
//display the current time
timelabel.Text<-timepart)
                
//adds the exit button to our form
timerform.Controls.Add(timelabel)
timerform.Controls.Add(exitbutton)
//when the exit button is clicked
exitbutton.Click.Add(fun quit->
//stops the time
timer1.Stop()
//close the form
timerform.Close())                   
//show our form
timerform.Show()
//execute our application
Application.Run(timerform)

Display the date part using the Remove function:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //use the F# library  
3. open System  
4. //use this to enable the intellisense. Very helpful in coding your application  
5. open System.Drawing   
6. //specify the location of the Form classes  
7. open System.Windows.Forms  
8. let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)  
9. //creates a form  
10. let dateform=new Form(Text="Display Date Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
11. //use the random function to generate random numbers  
12. let datelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)  
13.   
14. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)  
15.   
16. datelabel.Font<-ffont  
17. dateform.Load.Add(fun time->  
18. //assigns the current date and time to the datetime variable  
19. let datetime=Convert.ToString(System.DateTime.Now)  
20. //removes the text from the datetime variable staring from the 11 character  
21. let datepart=datetime.Remove(10)  
22. //display the current time  
23. datelabel.Text<-datepart)  
24.                   
25. //adds the exit button to our form  
26. dateform.Controls.Add(datelabel)  
27. dateform.Controls.Add(exitbutton)  
28. //when the exit button is clicked  
29. exitbutton.Click.Add(fun quit->dateform.Close())                     
30. //execute our application  
31. Application.Run(dateform)  

// Learn more about F# at http://fsharp.net
//use the F# library
open System
//use this to enable the intellisense. Very helpful in coding your application
open System.Drawing 
//specify the location of the Form classes
open System.Windows.Forms
let ffont=new Font("Verdana", 14.5F,FontStyle.Regular, GraphicsUnit.Point)
//creates a form
let dateform=new Form(Text="Display Date Part",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
//use the random function to generate random numbers
let datelabel=new Label(Location=new System.Drawing.Point(20,40),BorderStyle=BorderStyle.FixedSingle,AutoSize=true)

let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(200, 220),AutoSize=true)

datelabel.Font<-ffont
dateform.Load.Add(fun time->
//assigns the current date and time to the datetime variable
let datetime=Convert.ToString(System.DateTime.Now)
//removes the text from the datetime variable staring from the 11 character
let datepart=datetime.Remove(10)
//display the current time
datelabel.Text<-datepart)
                
//adds the exit button to our form
dateform.Controls.Add(datelabel)
dateform.Controls.Add(exitbutton)
//when the exit button is clicked
exitbutton.Click.Add(fun quit->dateform.Close())                   
//execute our application
Application.Run(dateform)

SystemSounds in F#

To play a system sound in Visual F#, use the SystemSounds object. For a simple example on using the SystemSounds object, try the following:

view plainprint?

1. // Learn more about F# at http://fsharp.net  
2. //use the f# standard library  
3. open System  
4. //use media classes  
5. open System.Media  
6. //specify the memory location of the classes used in drawing objects  
7. //required to draw the listbox item text  
8. open System.Drawing  
9. //specify the location of the form class  
10. open System.Windows.Forms  
11. //creates a form and assign a "Play System Sounds" caption to it  
12. let soundform=new Form(Text="Play System Sounds",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)  
13. //creates a label and set its Text to “Count”  
14. let lbl=new Label(Text="System sounds:", Location=new System.Drawing.Point(20,10),AutoSize=true)  
15. //makes a listbox  
16. let soundlistbox=new ListBox(Sorted=true,Location=new System.Drawing.Point(20,30),FormattingEnabled=true)  
17. //adds an item to the listbox when the form is loaded  
18. soundform.Load.Add(fun items->  
19.      //adds the items and ignore the passed index position values  
20.                     soundlistbox.Items.Add("Asterisk")|>ignore  
21.                     soundlistbox.Items.Add("Beep")|>ignore  
22.                     soundlistbox.Items.Add("Exclaimation")|>ignore  
23.                     soundlistbox.Items.Add("Hand")|>ignore  
24.                     soundlistbox.Items.Add("Question")|>ignore)  
25. soundlistbox.Click.Add(fun playsound->  
26.                     if soundlistbox.SelectedIndex=0 then  
27.                         SystemSounds.Asterisk.Play()  
28.                         MessageBox.Show("Asterisk", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)|>ignore  
29.                     if soundlistbox.SelectedIndex=1 then  
30.                         SystemSounds.Beep.Play()  
31.                         MessageBox.Show("Beep", "System Sounds", MessageBoxButtons.OK)|>ignore  
32.                     if soundlistbox.SelectedIndex=2 then  
33.                         SystemSounds.Exclamation.Play()  
34.                         MessageBox.Show("Exclaimation", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)|>ignore  
35.                     if soundlistbox.SelectedIndex=3 then  
36.                         SystemSounds.Hand.Play()  
37.                         MessageBox.Show("Hand", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Hand)|>ignore  
38.                     if soundlistbox.SelectedIndex=4 then  
39.                        SystemSounds.Question.Play()  
40.                         MessageBox.Show("Question", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Question)|>ignore)   
41.                                              
42. //displays the label to our form  
43. soundform.Controls.Add(lbl)        
44. //adds the listbox to our form      
45. soundform.Controls.Add(soundlistbox)             
46. soundform.Show()  
47. Application.Run(soundform)  

// Learn more about F# at http://fsharp.net
//use the f# standard library
open System
//use media classes
open System.Media
//specify the memory location of the classes used in drawing objects
//required to draw the listbox item text
open System.Drawing
//specify the location of the form class
open System.Windows.Forms
//creates a form and assign a "Play System Sounds" caption to it
let soundform=new Form(Text="Play System Sounds",StartPosition=FormStartPosition.CenterScreen,AutoScaleMode=AutoScaleMode.Font)
//creates a label and set its Text to “Count”
let lbl=new Label(Text="System sounds:", Location=new System.Drawing.Point(20,10),AutoSize=true)
//makes a listbox
let soundlistbox=new ListBox(Sorted=true,Location=new System.Drawing.Point(20,30),FormattingEnabled=true)
//adds an item to the listbox when the form is loaded
soundform.Load.Add(fun items->
     //adds the items and ignore the passed index position values
                    soundlistbox.Items.Add("Asterisk")|>ignore
                    soundlistbox.Items.Add("Beep")|>ignore
                    soundlistbox.Items.Add("Exclaimation")|>ignore
                    soundlistbox.Items.Add("Hand")|>ignore
                    soundlistbox.Items.Add("Question")|>ignore)
soundlistbox.Click.Add(fun playsound->
                    if soundlistbox.SelectedIndex=0 then
                        SystemSounds.Asterisk.Play()
                        MessageBox.Show("Asterisk", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)|>ignore
                    if soundlistbox.SelectedIndex=1 then
                        SystemSounds.Beep.Play()
                        MessageBox.Show("Beep", "System Sounds", MessageBoxButtons.OK)|>ignore
                    if soundlistbox.SelectedIndex=2 then
                        SystemSounds.Exclamation.Play()
                        MessageBox.Show("Exclaimation", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)|>ignore
                    if soundlistbox.SelectedIndex=3 then
                        SystemSounds.Hand.Play()
                        MessageBox.Show("Hand", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Hand)|>ignore
                    if soundlistbox.SelectedIndex=4 then
                       SystemSounds.Question.Play()
                        MessageBox.Show("Question", "System Sounds", MessageBoxButtons.OK, MessageBoxIcon.Question)|>ignore) 
                                           
//displays the label to our form
soundform.Controls.Add(lbl)      
//adds the listbox to our form    
soundform.Controls.Add(soundlistbox)           
soundform.Show()
Application.Run(soundform)

This will generate the following output: