Message passing of VC interprocess communication

Postmessge or SendMessage () for interprocess communication

Method 1:postmessge or SendMessage () message mechanism

Message sent in Project 1:

#define Wm_mymessage Wm_user + 1//the window class name of the target process (which can be viewed through the Spy + + tool) and the window name CWnd *pwnd = Cwnd::findwindow ("#32770", "mfctest"); if (NUL L! = pWnd) {pwnd->postmessage (wm_mymessage, NULL, NULL);} OR: HWND hwnd =:: FindWindow ("#32770", "mfctest"), if (NULL! = hwnd) {::P ostmessage (hwnd, wm_mymessage, NULL, NULL);}

Message received in Item 2:

. H declares that:

afx_msg LRESULT onmymessage (WPARAM WP, LPARAM LP);

Defined in. cpp:

Begin_message_map (CMainFrame, CFrameWnd) ...    On_message (Wm_mymessage, OnMyMessage)    

LRESULT cmfctestdlg::onmymessage (WPARAM WP, LPARAM LP) {AfxMessageBox ("Hello World"); return 0;}

Description

Using either PostMessage or SendMessage, the difference is that the SendMessage blocks until the target window program finishes processing the message and returns, and PostMessage sends a message to a thread's message queue and returns immediately. PostMessage is usually used, and SendMessage is better if the target process is to be detected.

Method 2: The message receiving end uses PreTranslateMessage () to handle

Send-side code:

#define Wm_mymessage Wm_user + 1//the window class name of the target process (which can be viewed through the Spy + + tool) and the window name CWnd *pwnd = Cwnd::findwindow ("#32770", "mfctest"); if (NUL L! = pWnd) {pwnd->postmessage (wm_mymessage, NULL, NULL);} OR: HWND hwnd =:: FindWindow ("#32770", "mfctest"), if (NULL! = hwnd) {::P ostmessage (hwnd, wm_mymessage, NULL, NULL);}

Receive-Side code:

. h Declaration

BOOL Cmfctestdlg::P retranslatemessage (msg* pMsg);

. CPP Definition

#define Wm_mymessage Wm_user + 1 BOOL cmfctestdlg::P retranslatemessage (msg* pMsg) {if (Pmsg->message =  Wm_user + 1 {AfxMessageBox ("Hello World");} Return CDialog::P retranslatemessage (PMSG);}

Description

The receive-side processing is placed in the PreTranslateMessage, so the sender must select PostMessage because the SendMessage message is not placed in the message queue, PreTranslateMessage can not receive this message.





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Message passing of VC interprocess communication