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.

Return Values

If an application processes this message, it should return zero.

Remarks

If the SetScrollPos or MoveWindow function is called for a child window as a result of the WM_SIZE message, the bRedraw parameter should be nonzero to cause the window to be repainted.

Although the width and height of a window are 32-bit values, the nWidth and nHeight parameters of the WM_SIZE message contain only the low-order 16 bits.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winuser.h.

See Also

Windows Overview, Window Messages, MoveWindow, SetScrollPos