//获得主窗口句柄
CWnd *pWnd = AfxGetMainWnd();
HWND hWnd = pWnd->GetSafeHwnd();
//在主窗口内搜索停靠窗口的句柄
CWnd *pDockWnd = CWnd::FindWindowEx(hWnd, NULL, NULL, _T("窗口名称"));
HWND hDockWnd = pDockWnd->GetSafeHwnd();
//在停靠窗口内搜索获得内部对话框句柄
CWnd *pWndDlg = CWnd::FindWindowEx(hDockWnd, NULL, _T("TestDlg"), NULL);
//必须进行强制类型转换,由CWnd指针转换为相应的控件类指针
CEdit *pEdit = (CEdit*)pWndDlg->GetDlgItem(IDC_EDIT);//必须进行强制类型转换