c++ - How to get the total time of an audio file?

Question

How to get the total time of an audio file? I am trying this:

QMediaPlayer* audioPlayer = new QMediaPlayer();
audioPlayer->setMedia(QUrl::fromLocalFile("F:/Audio/mysong.mp3"));
audioPlayer->duration(); // return 0

but all the time the function returns 0. I use the latest version Qt on Windows 8.

Answer 1

是的，我发现了错误，它是类型转换（qint64）为了获得您需要使用“durationChanged”信号的持续时间。

//get duration in durationChanged signal.
connect(audioPlayer, SIGNAL(positionChanged(qint64)), this, SLOT(setPositionSlider(qint64)));
//Old function
void Widget::setPositionSlider(qint64 i)
{
    ui->PositionSlider->setValue(i / duration * 100); //0 I thought it was converted into double.
}
//New function
void Widget::setPositionSlider(qint64 i)
{
    ui->PositionSlider->setValue(i / 1000);
}