Qt C++ QTimer不调用处理程序

Question

我在Qt C++中遇到QTimer问题,在我的代码中没有调用timeoutHandler().谁能告诉我为什么以及如何解决它？

Test.h

class Test : public QObject
{
    Q_OBJECT
private:
    static bool timeOuted;
public:
    explicit Test(QObject *parent = 0);
    virtual ~Test();
public slots:
    static void handleTimeout();
};

TEST.CPP

void Test::run()
{
    QTimer::singleShot(3000, this, SLOT(handleTimeout()));
    while(!timeOuted);
    if(timeOuted)
    {
        timeOuted = false;
    }
    else
    {
       /* some work */
    }
}

bool Test::timeOuted = false;

void Test::handleTimeout()
{
    static int i = 0;
    timeOuted = true;
    qDebug() << "TimeOuted " << i++;
}

Answer 1

QTimer需要Qt事件循环才能工作.当你进入时while(!timeOuted);,你无休止地阻止当前线程,Qt的事件循环没有机会采取任何行动(比如为计时器调用你的处理程序).这是你应该怎么做的:

Test.h:

class Test : public QObject
{
    Q_OBJECT
public:
    explicit Test(QObject *parent = 0);
    virtual ~Test();

    void run(); // <-- you missed this
private slots: // <-- no need to make this slot public
    void handleTimeout(); // <-- why would you make it static?!
};

TEST.CPP:

void Test::run()
{
    QTimer::singleShot(3000, this, SLOT(handleTimeout()));
}

void Test::handleTimeout()
{
    static int i = 0;
    qDebug() << "TimeOuted " << i++;

    /* some work */
}