**注释： [self.player play];一定要写在- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> )change context:(void )context 监听方法中，不然音频没有加载完成是无法播放的

//
//  TFPlayMusicManager.m
//  iOS-TutorTeacher
//
//  Created by kent J on 2017/6/28.
//  Copyright © 2017年 aizhikang. All rights reserved.
//#import "TFPlayMusicManager.h"
static TFPlayMusicManager *playerManager = nil;@implementation TFPlayMusicManager
#pragma mark - Private
+(TFPlayMusicManager *)defaultManager{static dispatch_once_t onceToken;dispatch_once(&onceToken, ^{playerManager = [[self alloc] init];});return playerManager;
}
// 当前是否正在录音
+(BOOL)isPlaying{return [[TFPlayMusicManager defaultManager] isPlaying];
}
-(BOOL)isPlaying{return !!_player;
}
// 播放
+ (void)asyncPlayMusicWithPreparePath:(NSString *)musicUrlcompletion:(void(^)(NSError *error))completion{[TFPlayMusicManager asyncPlayMusicWithPreparePath:musicUrl completion:completion];
}
// 停止播放
+(void)asyncStopMusicWithCompletion:(void(^)(NSString *recordPath))completion{[TFPlayMusicManager asyncStopMusicWithCompletion:completion];
}
// 取消录音
+(void)cancelCurrentRecording{[[TFPlayMusicManager defaultManager] cancelCurrentRecording];
}
// 取消录音
- (void)cancelCurrentRecording
{}
+(AVPlayer *)recorder{return [TFPlayMusicManager defaultManager].player;
}
// 开始播放，文件放到musicUrl下
- (void)asyncPlayMusicWithPreparePath:(NSString *)musicUrlcompletion:(void(^)(NSError *error))completion
{__weak TFPlayMusicManager *weakSelf = self;NSURL * url  = [NSURL URLWithString:musicUrl];self.playItem = [[AVPlayerItem alloc]initWithURL:url];self.player = [[AVPlayer alloc]initWithPlayerItem:self.playItem];self.playItem = self.player.currentItem;self.player.automaticallyWaitsToMinimizeStalling = NO;[self.playItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];[self.playItem addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];//添加播放进度观察者self.timeObserve = [self.player addPeriodicTimeObserverForInterval:CMTimeMake(1.0, 1.0) queue:dispatch_get_main_queue() usingBlock:^(CMTime time) {float current = CMTimeGetSeconds(time);float total = CMTimeGetSeconds(weakSelf.playItem.duration);if (current) {weakSelf.progress = current / total;weakSelf.playTime = [NSString stringWithFormat:@"%.f",current];weakSelf.playDuration = [NSString stringWithFormat:@"%.2f",total];}DebugLog(@"progress = %f playTime = %@ playDuration = %@",weakSelf.progress,weakSelf.playTime,weakSelf.playDuration);}];//    completion(completion);
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context {/*AVPlayerTimeControlStatusPaused,AVPlayerTimeControlStatusWaitingToPlayAtSpecifiedRate,AVPlayerTimeControlStatusPlaying*/if ([keyPath isEqualToString:@"status"]) {switch (self.player.status) {case AVPlayerStatusUnknown:DebugLog(@"KVO：未知状态，此时不能播放");break;case AVPlayerStatusReadyToPlay://                self.status = AVPlayerStatusReadyToPlay;{if (self.player.timeControlStatus == AVPlayerTimeControlStatusPlaying) {}DebugLog(@"KVO：准备完毕，可以播放   %ld++++++%@",(long)self.player.timeControlStatus,self.player.reasonForWaitingToPlay);[self.player play];}break;case AVPlayerStatusFailed:DebugLog(@"KVO：加载失败，网络或者服务器出现问题");break;default:break;}}if ([keyPath isEqualToString:@"loadedTimeRanges"]) {NSArray * array = self.playItem.loadedTimeRanges;CMTimeRange timeRange = [array.firstObject CMTimeRangeValue]; //本次缓冲的时间范围NSTimeInterval totalBuffer = CMTimeGetSeconds(timeRange.start) + CMTimeGetSeconds(timeRange.duration); //缓冲总长度DebugLog(@"共缓冲%.2f",totalBuffer);}}
//移除观察者
-(void)removeObserver{//    [self.playItem removeObserver:self forKeyPath:@"status"];if (_timeObserve) {[_player removeTimeObserver:_timeObserve];_timeObserve = nil;}
}
// 停止录音
-(void)asyncStopMusicWithCompletion:(void(^)(NSString *recordPath))completion{playFinish = completion;dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{[self->_player pause];});
}
#pragma mark - getter
- (NSDictionary *)recordSetting
{if (!_musicSetting) {_musicSetting = [[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithFloat: 11025.0],AVSampleRateKey, //采样率[NSNumber numberWithInt: kAudioFormatLinearPCM],AVFormatIDKey,[NSNumber numberWithInt:16],AVLinearPCMBitDepthKey,//采样位数 默认 16[NSNumber numberWithInt: 2], AVNumberOfChannelsKey,//通道的数目AVAudioQualityMin, AVEncoderAudioQualityKey,//通道的数目nil];}return _musicSetting;
}
-(instancetype)init{if (self = [super init]) {}return self;
}-(void)dealloc{DebugLog(@"内存释放");}
@end

**注释： [self.player play];一定要写在- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> )change context:(void )context 监听方法中，不然音频没有加载完成是无法播放的