private void InvalidateWindowRegion()
{
if (DesignMode)
return;
if (this.m_dummyControlPaintEventHandler == null)
this.m_dummyControlPaintEventHandler = this.DummyControl_Paint;
this.DummyControl.Paint += this.m_dummyControlPaintEventHandler;
this.DummyControl.Invalidate();
}