MFC學習（18）MFC中利用HWND_BROADCAST 向其它所有視窗廣播訊息
阿新 • • 發佈：2019-02-19
利用HWND_BROADCAST可以向其它程序,或DLL檔案的視窗等傳送訊息.
在MSDN中如此描述的:
Handle to the window whose window procedure will receive the message. If this parameter is HWND_BROADCAST, 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.
遮擋的視窗也可收到訊息.
首先要定義訊息:
必須使用RegisterWindowMessage,是Windows的註冊訊息變數;
如:
static UINT NEAR WM_OVER_LOAD= RegisterWindowMessage(_T("OVER_LOAD"));
其次巨集宣告為
ON_REGISTERED_MESSAGE(WM_OVER_LOAD, OnOverLoad) 函式宣告和普通訊息的函式宣告一樣
afx_msg LRESULT OnOverLoad(WPARAM wParam, LPARAM lParam);
傳送訊息例如:
::SendMessage( (HWND)HWND_BROADCAST,WM_OVER_LOAD, 引數1 ,引數2 );
::PostMessage( (HWND)HWND_BROADCAST,WM_OVER_LOAD, 引數1 ,引數2 );
如此所有的註冊了此訊息的視窗都可以收你發的訊息了