Problem with frame size. (working with notebook)

Hi , it seem that self.GetSize() doesn’t work on the frame so i’m asking if there someone that could explain it to me ?
I don’t find something that appear to work , i’m working only on notebook and when i try to refresh themselves the problem is that the notebook appear (i think) to give to self.GetSize the littlething that contain the label of this page, and when it’s the frame the value never changer even when it’s resize (the debug show it, it’s resized but still display the init value).
Ive tried to put a self.GetBestSize() to not have a absolute size but it is not working and same for notebook its completely killing them there is something that i’m supposed to know i think.

Ive got news, the problem is i need to call a self.Layout() (now i don’t understand the use of refresh because it work without it) now the problem is that there is no choice than using a wx.EXPAND to make the widget expand with the windows but the problem is i want my tree and my list to take more than one element in my gridsizer.
Before EXPAND and layout()

After
image
Now the button are thick but that’s not important the problem is that my list and tree can’t over rive other widget (like those who are invisible because to place my widget where i want i put empty widget all between them)