Winforms Grid Checkbox Single Selection

[Craig Finnigan]

I was having some trouble getting my checkbox slection to have a oncheck event that could be used to restrict the grid to have a single checkbox selected at any given time and process the change as soon as the value changed not after leaving the field. This is what I came up with.

Private Sub rgridAffinityPrograms_CellEditorInitialized(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.GridViewCellEventArgs) Handles rgridAffinityPrograms.CellEditorInitialized
        Dim editor As RadCheckBoxEditor = TryCast(e.ActiveEditor, RadCheckBoxEditor)
        AddHandler (editor.ValueChanged), AddressOf editor_ValueChanged
End Sub

Private Sub editor_ValueChanged(ByVal sender As Object, ByVal e As EventArgs)
        rgridAffinityPrograms.EndEdit()
End Sub

Private Sub rgridAffinityPrograms_CellValueChanged(ByVal sender As System.Object, ByVal e As Telerik.WinControls.UI.GridViewCellEventArgs) Handles rgridAffinityPrograms.CellValueChanged
        If e.ColumnIndex = 0 And sender.ToString = "Telerik.WinControls.UI.GridCheckBoxCellElement" Then
            Dim chk As GridCheckBoxCellElement = sender
            If chk.Value = True Then
                For Each row As GridViewRowInfo In rgridAffinityPrograms.Rows
                    If row.Index <> e.RowIndex Then
                        row.Cells("IsSelected").Value = False
                    End If
                Next
            End If
        End If
End Sub

[Stefan]

Hi Craig,

Thank you for sharing your solution with the community.

I would like to propose adding code which unsubscribes your from the ValueChanged event of the editor prior to subscribing to it, in order to avoid multiple subscriptions, since the editors in RadGridView are reused:

Private Sub rgridAffinityPrograms_CellEditorInitialized(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.GridViewCellEventArgs) Handles rgridAffinityPrograms.CellEditorInitialized
        Dim editor As RadCheckBoxEditor = TryCast(e.ActiveEditor, RadCheckBoxEditor)
        RemoveHandler (editor.ValueChanged), AddressOf editor_ValueChanged
        AddHandler (editor.ValueChanged), AddressOf editor_ValueChanged
End Sub

Another thing that you might do is keep the previously checked cell in a variable and reset just its state instead of iterating all cells in the column.

I hope that you find this information useful. Let us know if we can be of assistance.
 
Regards,
Stefan
the Telerik team