ios - 如何使AudioToolbox MusicTrack在iOS 9.0中循环播放？

此代码对于在iOS 8.4中循环播放MusicTrack效果很好，但是在通过MusicPlayerSetSequence设置音序时，会在iOS 9.0下暂停该应用

var loopInfo = MusicTrackLoopInfo(loopDuration: 1.0,numberOfLoops: 0)
            MusicTrackSetProperty(track, UInt32(kSequenceTrackProperty_LoopInfo), &loopInfo, UInt32(sizeofValue(loopInfo)))

有没有另一种方法可以让轨道在iOS 9中循环播放？

最佳答案

其他人也有类似的问题:https://forums.developer.apple.com/thread/9940当前解决方法的一般想法是，一旦到达轨道的末尾，就将播放标记设置回0。

例如，在用于启动音乐播放器的方法中使用以下命令:

MusicTrack track = NULL;
MusicTimeStamp trackLen = 0;
UInt32 trackLenLen = sizeof(trackLen);
//Get main track
MusicSequenceGetIndTrack(musicSequence, 0, &track);
//Get length of track
MusicTrackGetProperty(track, kSequenceTrackProperty_TrackLength, &trackLen, &trackLenLen);
//Create UserData for User Event with any data
static MusicEventUserData userData = {1, 0x09};
//Put new user event at the end of the track
MusicTrackNewUserEvent(track, trackLen, &userData);
//Set a callback for when User Events occur
MusicSequenceSetUserCallback(musicSequence, sequenceUserCallback, musicPlayer);

然后可以有一个回调函数:

static void sequenceUserCallback(void *inClientData,
                             MusicSequence             inSequence,
                             MusicTrack                inTrack,
                             MusicTimeStamp            inEventTime,
                             const MusicEventUserData *inEventData,
                             MusicTimeStamp            inStartSliceBeat,
                             MusicTimeStamp            inEndSliceBeat)
{
    [[NSOperationQueue mainQueue] addOperationWithBlock:^ {
        MusicPlayerSetTime((MusicPlayer) inClientData, 0.0);
    }];
}

这会将播放器设置回零。