WM_SIZE
The WM_SIZE message is sent to a window after its size has changed.
WM_SIZE
fwSizeType = wParam; // resizing flag
nWidth = LOWORD(lParam); // width of client area
nHeight = HIWORD(lParam); // height of client area
Parameters
fwSizeType
Value of wParam. Specifies the type of resizing requested. This parameter can be one of the following values: Value Meaning
SIZE_MAXHIDE Message is sent to all pop-up windows when some other window is maximized.
SIZE_MAXIMIZED The window has been maximized.
SIZE_MAXSHOW Message is sent to all pop-up windows when some other window has been restored to its former size.
SIZE_MINIMIZED The window has been minimized.
SIZE_RESTORED The window has been resized, but neither the SIZE_MINIMIZED nor SIZE_MAXIMIZED value applies.
nWidth
Value of the low-order word of lParam. Specifies the new width of the client area.
nHeight
Value of the high-order word of lParam. Specifies the new height of the client area.
