qt检测屏幕

    // 获取屏幕列表
    QList<QScreen*> screens = QGuiApplication::screens();
    qDebug() << "检测到屏幕数量:" << screens.count();

    for (int i = 0; i < screens.count(); ++i)
    {
        QScreen* screen = screens.at(i);

        // 获取设备像素比（关键！）
        qreal devicePixelRatio = screen->devicePixelRatio();

        // 计算真实的物理分辨率
        QSize physicalSize = screen->size() * devicePixelRatio;

        qDebug() << "屏幕" << i << ":" << screen->name();
        qDebug() << "  Qt报告分辨率:" << screen->size() << "(逻辑像素)";
        qDebug() << "  设备像素比:" << devicePixelRatio;
        qDebug() << "  真实物理分辨率:" << physicalSize << "(物理像素)";
        qDebug() << "  可用区域:" << screen->availableGeometry();
        qDebug() << "  屏幕位置:" << screen->geometry();
        qDebug() << "  物理尺寸:" << screen->physicalSize() << "mm";
        qDebug() << "  逻辑DPI:" << screen->logicalDotsPerInch();
        qDebug() << "  物理DPI:" << screen->physicalDotsPerInch();
        qDebug() << "----------------------------------------";
    }