Question

我正在尝试开发类似桌面分频器的应用。我使用了全局鼠标钩子（低级鼠标钩子），因为当拖动窗口进入特定位置后左键按下，窗口位于特定位置并调整大小。首先，当按下按钮时，我尝试将窗口重新定位到桌面屏幕的左下角。我使用SetWindowPos方法重新定位和调整大小，它不能很好地工作。当我释放左按钮时，窗口位于特定位置，但它立即返回到原始位置。在调试应用程序时，它会很好地进入屏幕的左下角。我不确切知道为什么会这样。以下是我的代码。

LRESULT CALLBACK LowLevelMouseProc(int code, WPARAM wParam, LPARAM lParam)
{
if ( code != HC_ACTION )
    return CallNextHookEx(hMouseHook, code, wParam, lParam);
switch (wParam)
{
    case WM_LBUTTONDOWN:
    {
        TRACE("Down\n");
        // To get window handle from current mouse position
        ::GetCursorPos(&mouse_pos);
        hCurrentWnd = ::WindowFromPoint(mouse_pos);

        LButton_Down = true;

        Window_Drag = false;    // Initialize Window_Drag variable
        Mouse_Drag = false;

        while (hCurrentWnd != 0)
        {
            style = ::GetWindowLong(hCurrentWnd, GWL_STYLE);
            const int x = style & (WS_POPUP | WS_CHILD);

            if ((x == WS_OVERLAPPED) || (x == WS_POPUP)) break;

            // we also want to manipulate mdi childs that
            // aren't maximized
            if ((!(style & WS_MAXIMIZE)) && (::GetWindowLong(hCurrentWnd, GWL_EXSTYLE) & WS_EX_MDICHILD)) break;

            hCurrentWnd = ::GetParent(hCurrentWnd);
        }

        if (IgnoreWindow())
        {
            return CallNextHookEx(hMouseHook, code, wParam, lParam);
        }

        // check if the alt key is pressed while a mouse button is pressed
        // and switch to the appropriate mode
        switch (wParam)
        {
            case WM_LBUTTONDOWN:
                LButton_Down = true;
                break;
            default:
                return CallNextHookEx(hMouseHook, code, wParam, lParam);
        }

        if (hCurrentWnd == 0)
        {
            return CallNextHookEx(hMouseHook, code, wParam, lParam);
        }

        HWND parent = ::GetParent(hCurrentWnd);

        // remember the window size and position 
        ::GetWindowRect(hCurrentWnd, &rDown);
        if ( ( parent ) && ( ( style & WS_POPUP ) == 0 ) )
        {
            ::ScreenToClient(parent, (POINT*)&rDown.left);
            ::ScreenToClient(parent, (POINT*)&rDown.right);
        }

        // we're getting serious - capture the mouse
        SetCapture(hCurrentWnd);

        return CallNextHookEx(hMouseHook, code, wParam, lParam);
    }

    case WM_MOUSEMOVE:
    {
        TRACE("Move\n");

        if ( !LButton_Down )
        {
            return CallNextHookEx(hMouseHook, code, wParam, lParam);
        }
        else {
            Mouse_Drag = true;

            TRACE("Mouse Drag - True\n");

            ::GetWindowRect(hCurrentWnd, &rCurWdrag);
            if ((rDown.left == rCurWdrag.left) && (rDown.top == rCurWdrag.top))
            {
                Window_Drag = false;
                TRACE("Window Drag - False\n");
            }
            else {
                Window_Drag = true;
                TRACE("Window Drag - True\n");
            }
        }

        return CallNextHookEx( hMouseHook, code, wParam, lParam) ;
    }

    case WM_LBUTTONUP:
    {
        TRACE("Up\n");

        LButton_Down = false;

        if ( Window_Drag && Mouse_Drag )
        {
            Window_Drag = false;
            Mouse_Drag = false;
            ::SetWindowPos(hCurrentWnd, 0, 0, 0, 500, 500, SWP_ASYNCWINDOWPOS);
            TRACE("Window Drag - False\n");
            TRACE("Mouse Drag - False\n");
        }
        else
        {
            Window_Drag = false;
            Mouse_Drag = false;
            TRACE("Window Drag 1 - False\n");
            TRACE("Mouse Drag 1 - False\n");
        }
        ReleaseCapture();
        return CallNextHookEx(NULL, code, wParam, lParam);
    }

    default:
    {

        LButton_Down = false;
        Window_Drag = false;
        Mouse_Drag = false;

        return CallNextHookEx(hMouseHook, code, wParam, lParam);
    }
}

}

这是全局鼠标挂钩的一部分

BOOL CMFCApplication4Dlg::OnInitDialog()
{
CDialogEx::OnInitDialog();

// Set the icon for this dialog.  The framework does this automatically
//  when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE);         // Set big icon
SetIcon(m_hIcon, FALSE);        // Set small icon

// TODO: Add extra initialization here

LButton_Down = false;
Mouse_Drag = false;
Window_Drag = false;

hMouseHook = SetWindowsHookEx(WH_MOUSE_LL, (HOOKPROC)LowLevelMouseProc, NULL, (DWORD)NULL);


return TRUE;  // return TRUE  unless you set the focus to a control
}

我该怎么办？

Answer 1

拖动窗口时，系统会向窗口发送消息 - WM_EXITSIZEMOVE。释放鼠标左键后，我将WM_EXITSIZEMOVE消息发送到捕获鼠标左键事件的窗口。完成此msg的过程后，我使用SetWindowPos方法重新定位窗口，这很有效。就是这样。

c ++：使用全局鼠标钩子重新定位窗口

1 个答案: