Question

I have a Data grid with DatagridComboBoxColumn , and i want to Fire Event SelectionChanged when user Select any thing From the ComboBox , Do Some operations ,
how can i do that any advice ,
thanks

Answer 1

You can handle your DataGridView’s EditingControlShowing event and cast the editing control to the ComboBox being displayed and then wire up its SelectionChangeCommitted event. Use the SelectionChangeCommitted handler do you what you need to do.

See the sample code in the MSDN article I linked for details.

Two important notes:

1. Despite the MSDN article’s sample code it’s best to use the
   ComboBox SelectionChangeCommitted event, as discussed here and in the
   comments of the linked MSDN article.

2. If you have more than one DatagridComboBoxColumn in your
   DataGridView you might want to determine which fired either your
   EditingControlShowing or the ComboBox’s SelectionChangeCommitted
   event. You can do this by checking your DGV
   CurrentCell.ColumnIndex property value.

I reworked the MSDN sample code a bit to show what I mean:

Private Sub DataGridView1_EditingControlShowing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DataGridView1.EditingControlShowing
    ' Only for a DatagridComboBoxColumn at ColumnIndex 1.
    If DataGridView1.CurrentCell.ColumnIndex = 1 Then
        Dim combo As ComboBox = CType(e.Control, ComboBox)
        If (combo IsNot Nothing) Then
            ' Remove an existing event-handler, if present, to avoid 
            ' adding multiple handlers when the editing control is reused.
            RemoveHandler combo.SelectionChangeCommitted, New EventHandler(AddressOf ComboBox_SelectionChangeCommitted)

            ' Add the event handler. 
            AddHandler combo.SelectionChangeCommitted, New EventHandler(AddressOf ComboBox_SelectionChangeCommitted)
        End If
    End If
End Sub

Private Sub ComboBox_SelectionChangeCommitted(ByVal sender As System.Object, ByVal e As System.EventArgs)
    Dim combo As ComboBox = CType(sender, ComboBox)
    Console.WriteLine("Row: {0}, Value: {1}", DataGridView1.CurrentCell.RowIndex, combo.SelectedItem)
End Sub