typedef struct tagCOPYDATASTRUCT {  // cds
    DWORD dwData; DWORD cbData; PVOID lpData;
} COPYDATASTRUCT;

LRESULT SendMessage(HWND hWnd,      // handle of destination windowUINT Msg,       // message to sendWPARAM wParam,  // first message parameterLPARAM lParam   // second message parameter
);

const char szDlgTitle[] = "ReceiveProcess";
HWND hRecvWindow  = ::FindWindow(NULL, szDlgTitle);

BOOL CCanCollectorDlg::OnCopyData(CWnd* pWnd, COPYDATASTRUCT* pCopyDataStruct)
{....
}

void CProcessCommDlg::OnBTNStart1()
{const char szDlgTitle[] = "ReceiveProcess";  HWND hSendWindow =this->GetSafeHwnd();HWND hRecvWindow  = ::FindWindow(NULL, szDlgTitle); COPYDATASTRUCT CopyData; char szSendBuf[100];  time_t  timenow; time(&timenow);  sprintf(szSendBuf, "%s", ctime(&timenow));//注意，ctime()返回的字符串后面带了'\n'  CopyData.dwData = 0;  CopyData.cbData = strlen(szSendBuf);  szSendBuf[CopyData.cbData - 1] = '\0';  CopyData.lpData = szSendBuf;  ::SendMessage(hRecvWindow, WM_COPYDATA, (WPARAM)hSendWindow, (LPARAM)&CopyData);  printf("%s\n", szSendBuf);  }

BEGIN_MESSAGE_MAP(CCanCollectorDlg, CDialog)//{{AFX_MSG_MAP(CCanCollectorDlg)
    ON_WM_SYSCOMMAND()ON_WM_PAINT()ON_WM_QUERYDRAGICON()ON_WM_COPYDATA()//}}AFX_MSG_MAP
END_MESSAGE_MAP()........BOOL CCanCollectorDlg::OnCopyData(CWnd* pWnd, COPYDATASTRUCT* pCopyDataStruct)
{char szBuffer[300];  memset(szBuffer, 0, sizeof(szBuffer));  sprintf(szBuffer, "dwData:%d cbData:%d\r\nlpData:0x%08x = %s\r\n\r\n",   pCopyDataStruct->dwData, pCopyDataStruct->cbData,   (PVOID)pCopyDataStruct->lpData, (char*)pCopyDataStruct->lpData);  return CDialog::OnCopyData(pWnd, pCopyDataStruct);
}