AVAudioPlayer时间显示

Question

我有一个通过AVAudioPlayer播放的简单mp3，我希望能够显示还剩多少时间。

我知道答案包括从AVAudioPlayer.currentTime中减去AVAudioPlayer.duration，但我不知道如何实现一个在播放时计算它的函数(我猜就像ActionScript中的onEnterFrame )。目前currentTime是静态的，即零。

Answer 1

我会去读NSTimer。将其安排为在媒体播放期间每秒运行一次，以便您可以根据剩余时间更新您的UI。

// Place this where you start to play
NSTimer * myTimer = [NSTimer scheduledTimerWithTimeInterval:1.0
                                                     target:self
                                                   selector:@selector(updateTimeLeft)
                                                   userInfo:nil
                                                    repeats:YES];

并创建用于更新UI的方法：

- (void)updateTimeLeft {
    NSTimeInterval timeLeft = self.player.duration - self.player.currentTime;

    // update your UI with timeLeft
    self.timeLeftLabel.text = [NSString stringWithFormat:@"%f seconds left", timeLeft];
}

Answer 2

我在swift中使用它，它起作用了：

// this for show remain time
let duration = Int((player1?.duration - (player1?.currentTime))!)
let minutes2 = duration/60
let seconds2 = duration - minutes2 * 60
durLabel.text = NSString(format: "%02d:%02d", minutes2,seconds2) as String

//this for current time
let currentTime1 = Int((player1?.currentTime)!)
let minutes = currentTime1/60
let seconds = currentTime1 - minutes * 60
curLabel.text = NSString(format: "%02d:%02d", minutes,seconds) as String