' Override the DataBindControl.
Public Overrides Sub DataBindControl( _
ByVal designerHost As IDesignerHost, _
ByVal control As Control)

    ' Create a reference, named dataSourceBinding,
    ' to the control's DataSource binding.
    Dim dataSourceBinding As DataBinding _
        = CType( _
        control, _
        IDataBindingsAccessor).DataBindings("DataSource")

    ' If the binding exists, create a reference to the
    ' list control, clear its ListItemCollection, and then add
    ' an item to the collection.
    If Not (dataSourceBinding Is Nothing) Then
        Dim simpleControl As SimpleRadioButtonList = _
            CType(control, SimpleRadioButtonList)

        simpleControl.Items.Clear()
        simpleControl.Items.Add("Data-bound Radio Button.")
    End If
End Sub