CallWindowProcA.3w

Langue: en

Version: Jun 2009 (debian - 07/07/09)

Section: 3 (Bibliothèques de fonctions)

NAME

CallWindowProcA (USER32.@)

SYNOPSIS

LRESULT CallWindowProcA
 (
  WNDPROC func,
  HWND    hwnd,
  UINT    msg,
  WPARAM  wParam,
  LPARAM  lParam
 )

PARAMS

func [In] window procedure.

hwnd [In] target window.

msg [In] message.

wParam [In] message dependent parameter.

[In] message dependent parameter.

DESCRIPTION

The CallWindowProc(3w) function invokes the Windows(tm) procedure _func_, with _hwnd_ as the target window, the message specified by _msg_, and the message parameters _wParam_ and _lParam_.

Some kinds of argument conversion may be done, I'm not sure what.

CallWindowProc() may be used for Windows(tm) subclassing. Use SetWindowLong() to set a new Windows(tm) procedure for Windows(tm) of the subclass, and handle subclassed messages in the new windows procedure. The new Windows(tm) procedure may then use CallWindowProc(3w) with _func_ set to the parent class's Windows(tm) procedure to dispatch the message to the superclass.

RETURNS

The return value is message dependent.

CONFORMANCE

ECMA-234, Win32

IMPLEMENTATION

Defined in "winuser.h".

Implemented in "dlls/user32/winproc.c".

Debug channel "win".