如何在Qt中设置声音

Question

我想播放声音，当second chages。

在我的stopwatch ，以milliseconds ，并且以miliseconds'变化（而不是seconds'变化）播放。 我应该为*seconds*创建一个条件 。

但是不能正确地做到这一点，您能建议这种情况吗？

这是我的方法 （将QMediaPlayer的对象 QMediaPlayer milliseconds ）：

我的构造函数和插槽：

StopMainWindow::StopMainWindow(QWidget *parent) :
    QMainWindow(parent),

      mRunning(false)
    , mStartTime()
    , mTotalTime(0)
{


    //ON THE TOP THERE ARE QPUSHBUTTONS AND QLABELS OBJECTS


    connect(pushButton_Start, SIGNAL(clicked()), SLOT(start()));
    connect(pushButton_go_on, SIGNAL(clicked()), SLOT(pause()));
    connect(pushButton_Stop, SIGNAL(clicked()), SLOT(stop()));
    connect(pushButton_Close, SIGNAL(clicked()), SLOT(close()));
    connect(pushButton_Back,SIGNAL(clicked()),SLOT(back()));
///////////////////////////////////////////////////////////////////////////////
    setCentralWidget(centralWidget);
///////////////////////////////////////////////////////////////////////////////////////////////
    pushButton_Start->setEnabled(true);
    pushButton_go_on->setEnabled(false);
    pushButton_Stop->setEnabled(false);
    startTimer(0);
}

StopMainWindow::~StopMainWindow()
{}
void StopMainWindow::start(void)
{
    pushButton_Start->setEnabled(false);
    pushButton_go_on->setEnabled(true);
    pushButton_Stop->setEnabled(true);
    mStartTime = QDateTime::currentDateTime();
    mRunning = true;
    QMediaPlayer *music=new QMediaPlayer();
    music->setMedia(QUrl("qrc:/sounds/tik.mp3"));
    music->play();
}



void StopMainWindow::stop(void)
{
    pushButton_Start->setEnabled(true);
    pushButton_go_on->setEnabled(true);
    pushButton_Stop->setEnabled(false);
    mTotalTime = 0;
    mRunning = false;
}
void StopMainWindow::pause(void)
{
    pushButton_Start->setEnabled(true);
    pushButton_go_on->setEnabled(false);
    pushButton_Stop->setEnabled(true);
    timerEvent(new QTimerEvent(0));
    mTotalTime += mSessionTime;
    mRunning = false;
}
void StopMainWindow::timerEvent(QTimerEvent *)
{

    if(mRunning)
    {

     mSessionTime = mStartTime.msecsTo(QDateTime::currentDateTime());
        qint64 time = mTotalTime + mSessionTime;
        time *= 111;

        unsigned int h = time / 1000 / 60 / 60;
        unsigned int m = (time / 1000 / 60) - (h * 60);
        unsigned int s = (time / 1000) - ((m + (h * 60))* 60);
        unsigned int ms = time - (s + ((m + (h * 60))* 60)) * 1000;

        const QString diff = QString("%1:%2:%3,%4").arg(h,  2, 10, QChar('0')).arg(m,  2, 10, QChar('0')).arg(s,  2, 10, QChar('0')).arg(ms, 3, 10, QChar('0'));
        mLabel->setText(diff);
    }

}

Answer 1

我建议仅初始化QMediaPlayer一次，并通过放置QMediaPlaylist::Loop使其连续运行来通过QMediaPlaylist添加声音，因为声音精确到一秒就不需要使用计时器。 当您希望QLabel每毫秒更改一次时，我们使用startTimer(1) 。 完整的例子 。

StopMainWindow::StopMainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::StopMainWindow)
{
    [...]

    connect(pushButton_Start, &QPushButton::clicked, this, &StopMainWindow::start);
    connect(pushButton_go_on, &QPushButton::clicked, this, &StopMainWindow::pause);
    connect(pushButton_Stop, &QPushButton::clicked, this, &StopMainWindow::stop);

    pushButton_Start->setEnabled(true);
    pushButton_go_on->setEnabled(false);
    pushButton_Stop->setEnabled(false);

    music=new QMediaPlayer(this,  QMediaPlayer::StreamPlayback);
    QMediaPlaylist *playlist = new QMediaPlaylist;
    playlist->addMedia(QUrl("qrc:/sounds/tik.mp3"));
    playlist->setPlaybackMode(QMediaPlaylist::Loop);

    music->setPlaylist(playlist);
    music->setVolume(100);

    mRunning = false;
}



void StopMainWindow::start()
{
    pushButton_Start->setEnabled(false);
    pushButton_go_on->setEnabled(true);
    pushButton_Stop->setEnabled(true);
    music->play();

    mRunning = true;

    mStartTime = QDateTime::currentDateTime();

    startTimer(1);
}

void StopMainWindow::pause()
{
    music->pause();
    mRunning = false;
    pushButton_Start->setEnabled(true);
    pushButton_go_on->setEnabled(false);
    pushButton_Stop->setEnabled(true);
    mTotalTime += mSessionTime;
}

void StopMainWindow::stop()
{
    pushButton_Start->setEnabled(true);
    pushButton_go_on->setEnabled(true);
    pushButton_Stop->setEnabled(false);

    music->stop();
    mRunning = false;
}

void StopMainWindow::timerEvent(QTimerEvent *event)
{
    Q_UNUSED(event)
    if(mRunning){
        mSessionTime = mStartTime.msecsTo(QDateTime::currentDateTime());
        qint64 time = mTotalTime + mSessionTime;
        time *= 111;

        unsigned int h = time / 1000 / 60 / 60;
        unsigned int m = (time / 1000 / 60) - (h * 60);
        unsigned int s = (time / 1000) - ((m + (h * 60))* 60);
        unsigned int ms = time - (s + ((m + (h * 60))* 60)) * 1000;

        const QString diff = QString("%1:%2:%3,%4").arg(h,  2, 10, QChar('0')).arg(m,  2, 10, QChar('0')).arg(s,  2, 10, QChar('0')).arg(ms, 3, 10, QChar('0'));
        mLabel->setText(diff);
    }
}