SendNotifyMessage.

SendNotifyMessage 

주요특징. 

대상 윈도우로 메시지 전송하나, SendNotifyMessage 호출하는 윈도우 스레드와 대상 윈도우 스레드에 따라 다른 리턴 방식. 

다른 스레드의 대상 윈도우인 경우 : 대상윈도우의 procedure 로 메시지 전달하고 즉시 리턴. 

동일 스레드의 대상 윈도우인 경우 : 대상윈도우의 procedure 로 메시지 전달하고 대상윈도우의 procedure 가 처리 완료한 이후 리턴됨.

SendNotifyMessage function

Sends the specified message to a window or windows. If the window was created by the calling thread, SendNotifyMessage calls the window procedure for the window and does not return until the window procedure has processed the message. If the window was created by a different thread, SendNotifyMessage passes the message to the window procedure and returns immediately; it does not wait for the window procedure to finish processing the message.

Syntax

C++

복사

BOOL WINAPI SendNotifyMessage(
  _In_ HWND   hWnd,
  _In_ UINT   Msg,
  _In_ WPARAM wParam,
  _In_ LPARAM lParam
);

Parameters

hWnd [in]

Type: HWND

A handle to the window whose window procedure will receive the message. If this parameter is HWND_BROADCAST ((HWND)0xffff), the message is sent to all top-level windows in the system, including disabled or invisible unowned windows, overlapped windows, and pop-up windows; but the message is not sent to child windows.

Msg [in]

Type: UINT

The message to be sent.

For lists of the system-provided messages, see System-Defined Messages.

wParam [in]

Type: WPARAM

Additional message-specific information.

lParam [in]

Type: LPARAM

Additional message-specific information.

Return value

Type:

Type: BOOL

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

If you send a message in the range below WM_USER to the asynchronous message functions (PostMessage, SendNotifyMessage, and SendMessageCallback), its message parameters cannot include pointers. Otherwise, the operation will fail. The functions will return before the receiving thread has had a chance to process the message and the sender will free the memory before it is used.

Applications that need to communicate using HWND_BROADCAST should use the RegisterWindowMessage function to obtain a unique message for inter-application communication.

The system only does marshalling for system messages (those in the range 0 to (WM_USER-1)). To send other messages (those >= WM_USER) to another process, you must do custom marshalling.

Requirements

Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Winuser.h (include Windows.h)
Library	User32.lib
DLL	User32.dll
Unicode and ANSI names	SendNotifyMessageW (Unicode) and SendNotifyMessageA (ANSI)

See also

Reference

PostMessage

PostThreadMessage

RegisterWindowMessage

SendMessage

SendMessageCallback

SendNotifyMessage

Conceptual

Messages and Message Queues

from : https://msdn.microsoft.com/ko-kr/library/windows/desktop/ms644953(v=vs.85).aspx

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