如何获取使用MPMusicPlayerController播放的播放歌曲的剩余时间？

Question

我想在我的应用程序中显示播放歌曲的剩余时间,我的代码:

NSTimeInterval currentTime= musicPlayer.currentPlaybackTime; 
NSNumber *duration = [musicPlayer.nowPlayingItem valueForProperty:MPMediaItemPropertyPlaybackDuration]; 
NSLog(@"Current Playback Time: %f",currentTime);

Answer 1

如果要重现音乐应用中显示的时间:

double nowPlayingItemDuration = [[[musicPlayer nowPlayingItem] valueForProperty:MPMediaItemPropertyPlaybackDuration]doubleValue];
double currentTime = (double) [musicPlayer currentPlaybackTime];
double remainingTime = nowPlayingItemDuration - currentTime;

NSString *timeElapsed;
NSString *timeRemaining;

if (nowPlayingItemDuration >= 3600.0) {
    timeElapsed = [NSString stringWithFormat: @"%02d:%02d:%02d",
                           (int)currentTime/3600,
                           (int) (currentTime/60)%60,
                           (int) currentTime%60];
    timeRemaining = [NSString stringWithFormat:@"- %02d:%02d:%02d",
                             (int)remainingTime/3600,
                             (int) (remainingTime/60)%60,
                             (int) remainingTime%60];

} else {
    timeElapsed = [NSString stringWithFormat: @"%02d:%02d",
                           (int) currentTime/60,
                           (int) currentTime%60];
    timeRemaining = [NSString stringWithFormat:@"- %02d:%02d",
                             (int) remainingTime/60,
                             (int) remainingTime%60];
}