How to add selection controls to your DataGrid

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Introduction

This will help you to understand how to add any type of control (ComboBox, DateTimePicker, CheckBox, RadioButton, etc.) to your DataGrid control. If you want, you can load data into some columns of the DataGrid from a database/XML file and add the controls to a separate column as a selection. By doing this, it will help you to reduce coding needed for validation since you are limiting data entry to a selection.

In the same time, you can capture events of those added controls and do whatever you want when firing those events.

Background

When I was asked to develop a configuration screen for an application, I faced so many difficulties while searching for 'how to add controls to the DataGrid'. I couldn't find any good complete article on this. After doing a long research on this, I was able to make a good methodology to do that. Without keeping it as a secret, I would like to share it with you all.

Using the code

The attached application contains all the code needed to run. Since some of the columns of the DataGrid are loading through a MS SQL Server � database, you need to change the server settings accordingly (server name, user ID and password).

And run the attached script on the Query Analyzer to create the database on the SQL Server.

//Capturing clicked cell into a locally defined variable.
Private hitTestGrid As DataGrid.HitTestInfo

All the controls which you wish to have on the DataGrid should be declared along "WithEvents" keyword, only if you are interested with their events to be captured.

Private WithEvents datagridtextBox As DataGridTextBoxColumn
Private WithEvents dataTable As dataTable
Private WithEvents comboControl As System.Windows.Forms.ComboBox
Private WithEvents dtp As New DateTimePicker
Private WithEvents chk As New CheckBox

Now we will see about capturing events and getting values to the DataGrid. (This code fragment shows you how to get value form a DateTimePicker and place it on the selected cell.)

Private Sub dtp_ValueChanged(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles dtp.ValueChanged
    dgMember(hitTestGrid.Row, hitTestGrid.Column) = dtp.Value.ToString
End Sub

Looping through available columns and determining on which cell you have clicked:

For i = 0 To dataTable.Rows.Count - 1
    sType = dgMember(i, 0).ToString()
    If hitTestGrid.Row = i Then
        Select Case hitTestGrid.Row
            Case 1
                datagridtextBox.TextBox.Controls.Add(dtp)
                dtp.BringToFront()
            Case 0
                datagridtextBox.TextBox.Controls.Add(comboControl)
                comboControl.BringToFront()
            Case 2
                datagridtextBox.TextBox.Controls.Add(chk)
                chk.BringToFront()
            Case 3
                datagridtextBox.TextBox.Controls.Add(rb)
                rb.BringToFront()
        End Select
    End If
    datagridtextBox.TextBox.BackColor = Color.White
Next i

Please look into the code, by that you will get a better picture about the concept.

Points of Interest

I learnt a lot about new features on .NET while writing this code. And I hope to do my VB.NET certification next week.

History

Initial version.