问题
I have created a window using the WS_EX_NOACTIVATE flag and it works great as far as not taking focus when you click the window. However when I drag the window or try to resize it, it doesn't redraw the window as your are moving and resizing it, only at the very end once you release the mouse button. Is there a way around this? I would like to see the window as I am resizing it. I have searched many documents, but I still don't find the resolution...
回答1:
It's a Windows bug. You need to call SetWindowPos(hwnd, 0, x, y, width, height, 0) on WM_MOVING. The coordinates to set are given to you in lParam which is a RECT*.
Note that doing this will activate the owned window and deactivate the owner, which is not what you want (and SWP_NOACTIVATE has no effect either).
To avoid that, you need to set WS_CHILD on the owned window. But set it after you created the window, via SetWindowLong(), otherwise your owned window will get clipped, like any child window.
And, as you probably already figured out, this only works for windows with WS_EX_TOOLWINDOW ex style. I wasn't able to make the owned window stay deactivated with any other style combination that doesn't include WS_EX_TOOLWINDOW.
That's winapi for you :(
回答2:
If you need a window that doesn't take focus when clicked, but can still be interacted with, you need to handle the WM_MOUSEACTIVATE, and return MA_NOACTIVATE.
Additional information and fully working sample code has been published by Raymond Chen. See How can I have a window that rejects activation but still receives pointer input?
来源：https://stackoverflow.com/questions/25051552/create-a-window-using-the-ws-ex-noactivate-flag-but-it-cant-be-dragged-until-i