WM_MDIGETACTIVE

An application sends the WM_MDIGETACTIVE message to a multiple document interface (MDI) client window to retrieve the handle to the active MDI child window.

WM_MDIGETACTIVE 
wParam = 0;                      // not used; must be zero 
lParam = (LPBOOL) lpfMaximized;  // optional pointer to maximized state flag 
 

Parameters

lpfMaximized

Value of lparam. This is an optional pointer to a maximized state flag variable. If lpfMaximized is non-NULL, the BOOL it points to is set to indicate the maximized state of the MDI child window. TRUE indicates that the window is maximized, FALSE indicates that it is not. This is equivalent to the indication supplied by the high-order word of the return value of the WM_MDIGETACTIVE message under 16-bit Windows. If lpfMaximized is NULL, the parameter is ignored.

Return Values

The return value is the handle to the active MDI child window.

Remarks

Note carefully a change in how this message indicates maximization. In 16-bit Windows, the message return value includes a flag indicating whether the MDI child window is maximized. In the Win32 API, the return value does not include this flag. Instead, the MDI child window's maximized state is indicated by setting a BOOL variable via the optional parameter in lParam, lpfMaximized.

QuickInfo

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

See Also

Multiple Document Interface Overview, Multiple Document Interface Messages