问题
Windows sends several messages when a window is resized:
- WM_GETMINMAXINFO
- WM_ENTERSIZEMOVE
- WM_EXITSIZEMOVE
- WM_NCCALCSIZE
- WM_SIZING
- WM_SIZE
- WM_WINDOWPOSCHANGING
- WM_WINDOWPOSCHANGED
and possibly more.
If I would like to re-position the children when my window is resized, where and how should I do so?
I'm looking for the "best" method -- i.e. the method with the fewest gotcha's and the least flicker.
My current method is to perform all the repositioning inside WM_NCCALCSIZE, using DeferWindowPos.
However, I've also tried handling it inside WM_WINDOWPOSCHANGED... but no matter where I handle it, it seems like there is always at least one "moment" when the window is painted in an in-between state, where the window's size has changed, but its contents have yet to be resized.
Another effect I would also like to avoid: moving a child after it has already moved. I don't want the user to see a control sliding down and then back up because of my change -- it should have as few transient effects as possible.
Am I doing this correctly? Is there a better place I can lay out the window's children?
回答1:
You should re-position the window in the WM_SIZE message, because that is the last one that the window recieves before complete it's task...To re-position the window you can use MoveWindow
来源：https://stackoverflow.com/questions/10873236/when-and-how-to-lay-out-the-children-of-a-win32-window-in-response-to-a-resize