UInt32 sessionCategory = kAudioSessionCategory_MediaPlayback;AudioSessionSetProperty(kAudioSessionProperty_AudioCategory,                        sizeof(sessionCategory),                        &sessionCategory);UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,                         sizeof (audioRouteOverride),                         &audioRouteOverride);AVAudioSession *audioSession = [AVAudioSession sharedInstance];//默认情况下扬声器播放[audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];[audioSession setActive:YES error:nil];NSError *playerError;  //    self.player = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL URLWithString:[VoiceRecorderBaseVC getPathByFileName:recordedFile ofType:@"aac"]] error:&playerError];self.player.meteringEnabled = YES;if (self.player == nil){    NSLog(@"ERror creating player: %@", [playerError description]);}[self handleNotification:YES];self.player.delegate = self;self.player.volume = 1;[self.player play];复制代码

#pragma mark - 监听听筒or扬声器 - (void) handleNotification:(BOOL)state { [[UIDevice currentDevice] setProximityMonitoringEnabled:state]; //建议在播放之前设置yes，播放结束设置NO，这个功能是开启红外感应

if(state)//添加监听    [[NSNotificationCenter defaultCenter] addObserver:self                                             selector:@selector(sensorStateChange:) name:@"UIDeviceProximityStateDidChangeNotification"                                               object:nil];else//移除监听    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"UIDeviceProximityStateDidChangeNotification" object:nil];}复制代码

//处理监听触发事件

-(void)sensorStateChange:(NSNotificationCenter *)notification;{  //如果此时手机靠近面部放在耳朵旁，那么声音将通过听筒输出，并将屏幕变暗（省电啊）    if ([[UIDevice currentDevice] proximityState] == YES)    {        NSLog(@"Device is close to user");        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];    }    else    {      NSLog(@"Device is not close to user");      [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];    }}复制代码