RibbonTab hide problem

[matom]

Hi,

there is a problem in my application, you can see the problem in the pictures. (focus the bottom of two pictures)
when the visuals of tab is display, everything is fine. but when the tab is hide, something wrong.
I don't know what happened. It likes something hide the bottom of panel.
this problem is only display when the windowstate is Maximized.

[matom]

I'm sorry, it's my problem.
I create a Graphics object named m_g in the Initialize Function use panel.CreateGraphics(). When the panel size chaged, m_g is not updated at the same time. m_g.VisibleClipBounds still use the old value. that's the reason.
I was feazed by this problem for a long time. I'm happy to solve it today.