Overriding PerformDataBinding on Custom ServerControls

I ran into something cool today.  If you Override PerformDataBinding you have access to the DataSource that populated your ListControl.  In my case, I extended RadioButtonList and connected it to an ObjectDataSource that retrieves a List(Of MyObjects) and in the debugger, there was my list of MyObjects in the dataSource collection!

 

        Protected Overrides Sub PerformDataBinding(ByVal dataSource As System.Collections.IEnumerable)

            MyBase.PerformDataBinding(dataSource)

        End Sub

 

I guess this would be a good time to mention that I was able to handle the ArgumentOutOfRangeException that occurs when you bind a RadioButtonList and the ListItem doesn’t exist by Overriding OnDataBinding:

 

        Protected Overrides Sub OnDataBinding(ByVal e As EventArgs)

            Try

                MyBase.OnDataBinding(e)

            Catch ex As ArgumentOutOfRangeException

                Me.ClearSelection()

            End Try

        End Sub