linux qt 检测U盘热插拔的方法与代码

可以使用Linux下的udev来检测U盘的插拔，并通过Qt的信号槽机制实现。

以下是一个简单的示例代码：

#include <QtCore/QCoreApplication>
#include <QtCore/QDebug>
#include <QtCore/QSocketNotifier>
#include <QtCore/QDir>
#include <QtCore/QFile>
#include <QtCore/QRegExp>

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <libudev.h>

class UdevMonitor : public QObject
{
    Q_OBJECT
public:
    explicit UdevMonitor(QObject *parent = 0)
        : QObject(parent)
        , m_udevContext(udev_new())
    {
        if (!m_udevContext) {
            qCritical() << "Failed to create udev context.";
            return;
        }

        m_udevMonitor = udev_monitor_new_from_netlink(m_udevContext, "udev");
        if (!m_udevMonitor) {
            qCritical() << "Failed to create udev monitor.";
            return;
        }

        udev_monitor_filter_add_match_subsystem_devtype(m_udevMonitor, "block", "disk");

        if (udev_monitor_enable_receiving(m_udevMonitor) < 0) {
            qCritical() << "Failed to enable udev monitoring.";
            return;
        }

        m_notifier = new QSocketNotifier(udev_monitor_get_fd(m_udevMonitor), QSocketNotifier::Read, this);
        connect(m_notifier, &QSocketNotifier::activated, this, &UdevMonitor::handleUdevEvent);
    }

    ~UdevMonitor()
    {
        if (m_notifier)
            delete m_notifier;

        if (m_udevMonitor)
            udev_monitor_unref(m_udevMonitor);

        if (m_udevContext)
            udev_unref(m_udevContext);
    }

signals:
    void deviceAdded(const QString &devicePath);
    void deviceRemoved(const QString &devicePath);

private slots:
    void handleUdevEvent()
    {
        struct udev_device *udevDevice = udev_monitor_receive_device(m_udevMonitor);
        if (udevDevice) {
            QString devicePath = QString::fromUtf8(udev_device_get_devnode(udevDevice));
            QString action = QString::fromUtf8(udev_device_get_action(udevDevice));

            if (action == "add")
                emit deviceAdded(devicePath);
            else if (action == "remove")
                emit deviceRemoved(devicePath);

            udev_device_unref(udevDevice);
        }
    }

private:
    struct udev *m_udevContext = nullptr;
    struct udev_monitor *m_udevMonitor = nullptr;
    QSocketNotifier *m_notifier = nullptr;
};

int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);

    UdevMonitor monitor;
    QObject::connect(&monitor, &UdevMonitor::deviceAdded, [](const QString &devicePath) {
        qDebug() << "Device added:" << devicePath;
    });
    QObject::connect(&monitor, &UdevMonitor::deviceRemoved, [](const QString &devicePath) {
        qDebug() << "Device removed:" << devicePath;
    });

    return app.exec();
}

#include "main.moc"

这个示例代码使用了libudev库来监听U盘的插拔事件，当U盘插入或拔出时，会发出相应的信号。你可以在deviceAdded和deviceRemoved信号的槽函数中做出相应的处理，比如挂载或卸载U盘。