程式間通訊的WM_COPYDA他的使用

http://blog.csdn.net/ao929929fei/article/details/6316174

 

接收資料的一方

ON_WM_COPYDATA()

afx_msg BOOL OnCopyData(CWnd* pWnd, COPYDATASTRUCT* pCopyDataStruct);

程式碼片段：

 

BOOL CClientDemoDlg::OnCopyData(CWnd* pWnd, COPYDATASTRUCT* pCopyDataStruct)
{
    if (pCopyDataStruct != NULL)
    {
        LPCTSTR pszText = (LPCTSTR)(pCopyDataStruct->lpData);
        DWORD dwLength = (DWORD)(pCopyDataStruct->cbData);
        TCHAR szRecvText[1024] = {0};
        memcpy(szRecvText, pszText, dwLength);
        MessageBox(szRecvText, _T("Test"), MB_OK);
    }

    return CDialog::OnCopyData(pWnd, pCopyDataStruct);
}

 

 

傳送資料的一方

程式碼片段：

 

CString strWindowTitle =  _T("ClientDemo");
    CString strDataToSend = _T("Hello, Everyone fsdfsdfsdfdsfds,this is a test demo!");

    HWND hOtherWnd = ::FindWindow(NULL, strWindowTitle.GetBuffer(0));
    if (hOtherWnd != NULL && ::IsWindow(hOtherWnd))
    {
        COPYDATASTRUCT cpd;
        cpd.dwData = 0;
        cpd.cbData = strDataToSend.GetLength() * sizeof(TCHAR);
        cpd.lpData = (void*)strDataToSend.GetBuffer(0);
        HRESULT hResult = ::SendMessage(hOtherWnd, WM_COPYDATA, (WPARAM)(AfxGetApp()->m_pMainWnd), (LPARAM)&cpd);
        strDataToSend.ReleaseBuffer();
    }

OK了，就這麼簡單

 

WM_COPYDATA訊息主要目的是允許在程式間傳遞少量只讀資料。SDK文件推薦使用者使用SendMessage()函式，接收方在資料複製完成前不返回，這樣傳送方就不可能刪除和修改資料。