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:

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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:

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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:

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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:

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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: