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用SendMessage发WM_COPYDATA消息

作者:互联网

转载:https://www.cctry.com/thread-78882-1-1.html

发送方:

 1 CString str="这是我要发送的给另外一个进程字符串。";
 2 COPYDATASTRUCT myCopyDATA;
 3 myCopyDATA.cbData=str.GetLength();
 4 myCopyDATA.lpData=str.GetBuffer(0);
 5 str.ReleaseBuffer();
 6 HWND hwnd=::FindWindow(NULL,"Receive"); //假设目标程序窗口标题为"Receive"
 7 if (hwnd)
 8 ::SendMessage(hwnd,WM_COPYDATA,NULL,(LPARAM)&myCopyDATA);
 9 else
10 AfxMessageBox("目标程序没有运行。");

接收消息的程序(这里假设是基于对话框的工程)请按如下步骤来实现:

先给对话框类CReceiveDlg(如果你的接收程序为SDI工程的话,把CReceiveDlg类换成CMainFrame类)添加一个消息处理函数LRESULT OnReceive(WPARAM wParam,LPARAM lParam),代码如下:

 1 LRESULT CReceiveDlg::OnReceive(WPARAM wParam,LPARAM lParam)
 2 {
 3 COPYDATASTRUCT *p = NULL ;
 4 p = (COPYDATASTRUCT*)lParam;
 5 CString strTemp;
 6 memcpy(strTemp.GetBuffer((int)p->cbData),p->lpData,p->cbData);
 7 strTemp.ReleaseBuffer();
 8 AfxMessageBox(strTemp);
 9 return 0;
10 }

接着再给工程设定刚才添加的函数OnReceive为WM_COPYDATA消息的响应函数,在ReceiveDlg.cpp文件中如下地方加入一行代码:

1 BEGIN_MESSAGE_MAP(CReceiveDlg, CDialog)
2 //{{AFX_MSG_MAP(CReceiveDlg)
3 ON_WM_PAINT()
4 ON_WM_QUERYDRAGICON()
5 ON_MESSAGE(WM_COPYDATA,OnReceive) //只要添加这一行进行WM_COPYDATA消息映射
6 //}}AFX_MSG_MAP
7 END_MESSAGE_MAP()

好了,现在分别运行两个程序,应该可以在A程序中给B程序发送消息了,B收到消息后会弹出个MessageBox来显示从A程序发送来消息了。

 

注:

COPYDATASTRUCT *p = NULL ;
p = (COPYDATASTRUCT*)lParam;

这里如果写成

COPYDATASTRUCT p =  (COPYDATASTRUCT &)lParam;

编译时不会报错,但是得到的数据错误

 

标签:lParam,MAP,WM,SendMessage,COPYDATASTRUCT,COPYDATA,CReceiveDlg
来源: https://www.cnblogs.com/Toya/p/15464593.html