Skip to content

Latest commit

 

History

History
138 lines (97 loc) · 3.81 KB

nf-winuser-defwindowproca.md

File metadata and controls

138 lines (97 loc) · 3.81 KB
Raw
UID title description helpviewer_keywords old-location tech.root ms.assetid ms.date ms.keywords req.header req.include-header req.target-type req.target-min-winverclnt req.target-min-winversvr req.kmdf-ver req.umdf-ver req.ddi-compliance req.unicode-ansi req.idl req.max-support req.namespace req.assembly req.type-library req.lib req.dll req.irql targetos req.typenames req.redist ms.custom f1_keywords dev_langs topic_type api_type api_location api_name req.apiset
NF:winuser.DefWindowProcA
DefWindowProcA function (winuser.h)
Calls the default window procedure to provide default processing for any window messages that an application does not process. (ANSI)
DefWindowProcA
winuser/DefWindowProcA
winmsg\defwindowproc.htm
winmsg
VS|winui|~\winui\windowsuserinterface\windowing\windowprocedures\windowprocedurereference\windowprocedurefunctions\defwindowproc.htm
12/05/2018
DefWindowProc, DefWindowProc function [Windows and Messages], DefWindowProcA, DefWindowProcW, _win32_DefWindowProc, _win32_defwindowproc_cpp, winmsg.defwindowproc, winui._win32_defwindowproc, winuser/DefWindowProc, winuser/DefWindowProcA, winuser/DefWindowProcW
winuser.h
Windows.h
Windows
Windows 2000 Professional [desktop apps only]
Windows 2000 Server [desktop apps only]
DefWindowProcW (Unicode) and DefWindowProcA (ANSI)
User32.lib
User32.dll
Windows
19H1
DefWindowProcA
winuser/DefWindowProcA
c++
APIRef
kbSyntax
DllExport
User32.dll
API-MS-Win-NTUser-IE-Window-l1-1-0.dll
ie_shims.dll
API-MS-Win-RTCore-NTUser-Window-l1-1-0.dll
minuser.dll
Ext-MS-Win-NTUser-Window-l1-1-0.dll
Ext-MS-Win-NTUser-Window-l1-1-1.dll
Ext-MS-Win-NTUser-Window-l1-1-2.dll
Ext-MS-Win-RTCore-NTUser-Window-Ext-l1-1-0.dll
ext-ms-win-ntuser-window-l1-1-3.dll
Ext-MS-Win-NTUser-Window-L1-1-4.dll
DefWindowProc
DefWindowProcA
DefWindowProcW
ext-ms-win-ntuser-window-l1-1-0 (introduced in Windows 8)

DefWindowProcA function

-description

Calls the default window procedure to provide default processing for any window messages that an application does not process. This function ensures that every message is processed. DefWindowProc is called with the same parameters received by the window procedure.

-parameters

-param hWnd [in]

Type: HWND

A handle to the window procedure that received the message.

-param Msg [in]

Type: UINT

The message.

-param wParam [in]

Type: WPARAM

Additional message information. The content of this parameter depends on the value of the Msg parameter.

-param lParam [in]

Type: LPARAM

Additional message information. The content of this parameter depends on the value of the Msg parameter.

-returns

Type: LRESULT

The return value is the result of the message processing and depends on the message.

-syntax

LRESULT DefWindowProcA(
  [in] HWND   hWnd,
  [in] UINT   Msg,
  [in] WPARAM wParam,
  [in] LPARAM lParam
);

-see-also

CallWindowProc

Conceptual

DefDlgProc

Reference

Window Procedures

WindowProc

-remarks

Note

The winuser.h header defines DefWindowProc as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.