bsp;    case WM_CREATE:  

            //将本窗口注册到Clipboard Viewer Chain，

            //并保存Clipboard Viewer Chain中下一个窗口的句柄

            hwndNextViewer = SetClipboardViewer(hWnd);

            break;

        case WM_CHANGECBCHAIN:  //Clipboard Viewer注销

            //如果注销的Clipboard Viewer窗口是本窗口的下一个窗口，

            //则修改本窗口保存的下一个窗口句柄,

            //否则将该消息传递到Clipboard Viewer Chain的下一个窗口

            if ((HWND) wParam == hwndNextViewer)

                hwndNextViewer = (HWND) lParam;

            else if (hwndNextViewer != NULL)

                SendMessage(hwndNextViewer, message, wParam, lParam);  

            break;

        case WM_DRAWCLIPBOARD:  //剪贴板内容变化

            //触发ON_PAINT显示URL内容

            InvalidateRect(hWnd, NULL, TRUE);

            UpdateWindow(hWnd);

            //否则将该消息传递到Clipboard Viewer Chain的下一个窗口

            SendMessage(hwndNextViewer, message, wParam, lParam);

            break;

        case WM_DESTROY:

            //从Clipboard Viewer Chain注销本窗口

            ChangeClipboardChain(hWnd, hwndNextViewer);

            PostQuitMessage(0);

            break;

        //----------------------------------------------------------------

        case WM_COMMAND:

            wmId    = LOWORD(wParam