Yet another way of binding a control to a field name in Visual F#

On my last post, I’ve shown you how to bind a record value to a control using the DataBindings method. Another way of binding a control to a fieldname is by using Text property of a control and assigning the dataset collection properties as its value:

Syntax:

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1. controlobjvariable.Text<- (datasetname.Tables.["tablename"].Rows.Item(rowindexnumber).Item(columnindexnumber))  

controlobjvariable.Text<- (datasetname.Tables.["tablename"].Rows.Item(rowindexnumber).Item(columnindexnumber))

For instance:

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1. emplabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(0))  

emplabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(0))

The rowindexnumber of the first record on your table is 0, the second record is 1 and so on. Same goes with the columnindexnumber. For a simple example of application that uses the binding method above, follow these steps(I assume here that you have already created a database file named “dbEmployee” and a table named “tblEmployee”):
1. Click Start>All Programs>Microsoft Visual Studio 2008>Microsoft Visual Studio 2008.
2. Click File>New>Project>Select Visual F# in the project types>Select F# application in the Visual Studio installed templates category.
3. Click the Project menu>Add reference>Click the .Net tab>Locate then double-click System.Windows.Forms. Do step 3 again and this time, select System.Drawing and System.Data from the .Net tab.
4. Enter the following code after the line “// Learn more about F# at http://fsharp.net “:

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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  
5. open System.Windows.Forms  
6. open System.Data  
7. open System.Drawing  
8. open System.Data.OleDb  
9. //creates a font  
10. let ffont=new Font("Verdana", 9.75F,FontStyle.Regular, GraphicsUnit.Point)    
11. //creates a connection object  
12. let oleconn = new System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;  
13.   Data Source=C:\Documents and Settings\Administrator\My Documents\dbEmployee.mdb")  
14.  //creates an OleDbDataAdapter  
15. let dataadpter = new System.Data.OleDb.OleDbDataAdapter("Select * from tblEmployee", oleconn)  
16. let deletecommand=new System.Data.OleDb.OleDbCommand()  
17.   
18. //generates a dataset  
19. let dataset11 = new DataSet()  
20. //fills the dataset with recod values  
21. dataadpter.Fill(dataset11,"tblEmployee")|>ignore  
22. //creates a form  
23. let dataform = new Form(Text="Bind Form Control Part 2",AutoScaleDimensions=new System.Drawing.SizeF(60.0F, 13.0F),ClientSize=new System.Drawing.Size(300, 200),StartPosition=FormStartPosition.CenterScreen)  
24. //creates our controls  
25. let exitbutton=new Button(Text="Exit", Location=new System.Drawing.Point(190, 170))    
26. let label1=new Label(Text="Employee number:",Location=new System.Drawing.Point(0, 10),AutoSize=true)  
27. let label2=new Label(Text="Firstname:",Location=new System.Drawing.Point(0, 50),AutoSize=true)  
28. let label3=new Label(Text="Lastname:",Location=new System.Drawing.Point(0,100),AutoSize=true)  
29. let emplabel=new Label(Location=new System.Drawing.Point(140,10),BorderStyle=BorderStyle.FixedSingle)  
30. let fnamelabel=new Label(Location=new System.Drawing.Point(100,50),BorderStyle=BorderStyle.FixedSingle)  
31. let lnamelabel=new Label(Location=new System.Drawing.Point(100,100),BorderStyle=BorderStyle.FixedSingle)  
32. //assings the font to our form  
33. dataform.Font<-ffont  
34. //adds the controls to our form  
35. dataform.Controls.Add(exitbutton)  
36. dataform.Controls.Add(label1)  
37. dataform.Controls.Add(label2)  
38. dataform.Controls.Add(label3)  
39. dataform.Controls.Add(emplabel)  
40. dataform.Controls.Add(fnamelabel)  
41. dataform.Controls.Add(lnamelabel)  
42.   
43. //binds the fieldnames to our label  
44. emplabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(0))  
45. fnamelabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(1))  
46. lnamelabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(2))  
47.   
48. //when the exit button is clicked  
49. exitbutton.Click.Add(fun exit->  
50. //close the form and dataconnection  
51.                     dataform.Close()  
52.                     oleconn.Close())  
53.   
54. //executes our application  
55. dataform.Show()  
56. Application.Run(dataform)  

// 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
open System.Windows.Forms
open System.Data
open System.Drawing
open System.Data.OleDb
//creates a font
let ffont=new Font("Verdana", 9.75F,FontStyle.Regular, GraphicsUnit.Point)  
//creates a connection object
let oleconn = new System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;
  Data Source=C:\Documents and Settings\Administrator\My Documents\dbEmployee.mdb")
 //creates an OleDbDataAdapter
let dataadpter = new System.Data.OleDb.OleDbDataAdapter("Select * from tblEmployee", oleconn)
let deletecommand=new System.Data.OleDb.OleDbCommand()

//generates a dataset
let dataset11 = new DataSet()
//fills the dataset with recod values
dataadpter.Fill(dataset11,"tblEmployee")|>ignore
//creates a form
let dataform = new Form(Text="Bind Form Control Part 2",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 label1=new Label(Text="Employee number:",Location=new System.Drawing.Point(0, 10),AutoSize=true)
let label2=new Label(Text="Firstname:",Location=new System.Drawing.Point(0, 50),AutoSize=true)
let label3=new Label(Text="Lastname:",Location=new System.Drawing.Point(0,100),AutoSize=true)
let emplabel=new Label(Location=new System.Drawing.Point(140,10),BorderStyle=BorderStyle.FixedSingle)
let fnamelabel=new Label(Location=new System.Drawing.Point(100,50),BorderStyle=BorderStyle.FixedSingle)
let lnamelabel=new Label(Location=new System.Drawing.Point(100,100),BorderStyle=BorderStyle.FixedSingle)
//assings the font to our form
dataform.Font<-ffont
//adds the controls to our form
dataform.Controls.Add(exitbutton)
dataform.Controls.Add(label1)
dataform.Controls.Add(label2)
dataform.Controls.Add(label3)
dataform.Controls.Add(emplabel)
dataform.Controls.Add(fnamelabel)
dataform.Controls.Add(lnamelabel)

//binds the fieldnames to our label
emplabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(0))
fnamelabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(1))
lnamelabel.Text<-Convert.ToString(dataset11.Tables.["tblEmployee"].Rows.Item(0).Item(2))

//when the exit button is clicked
exitbutton.Click.Add(fun exit->
//close the form and dataconnection
                    dataform.Close()
                    oleconn.Close())

//executes our application
dataform.Show()
Application.Run(dataform)

5. This will display the following output: