public void ToolkitMdiActivate(IToolkitWindow child)
{
IToolkitEventSink co = this.mControlWeakRef.Target as IToolkitEventSink;
if (null != co)
{
co.ToolkitMdiActivate(child);
}
}
protected override void OnActivateChild(TopLevelWindow child)
{
sink.ToolkitMdiActivate((IToolkitWindow)child);
}