The WM_WINDOWPOSCHANGED message is sent to a window whose size, position, or place in the Z order has changed as a result of a call to the SetWindowPos function or another window-management function.
WM_WINDOWPOSCHANGED
lpwp = (LPWINDOWPOS) lParam; // points to size and position data
Parameters
lpwp
Value of lParam. Points to a WINDOWPOS structure that contains information about the window's new size and position.
Return Values
If an application processes this message, it should return zero.
Default Action
The DefWindowProc function sends the WM_SIZE and WM_MOVE messages to the window.
Remarks
The WM_SIZE and WM_MOVE messages are not sent if an application handles the WM_WINDOWPOSCHANGED message without calling DefWindowProc. It is more efficient to perform any move or size change processing during the WM_WINDOWPOSCHANGED message without calling DefWindowProc.
See Also
DefWindowProc, EndDeferWindowPos, SetWindowPos, WINDOWPOS, WM_MOVE, WM_SIZE, WM_WINDOWPOSCHANGING