[[UIDevice currentDevice] setProximityMonitoringEnabled:YES]; //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
2
3 //添加监听
4 [[NSNotificationCenter defaultCenter] addObserver:self
5 selector:@selector(sensorStateChange:)
6 name:@"UIDeviceProximityStateDidChangeNotification"
7 object:nil];
8
9 //处理监听触发事件
10 -(void)sensorStateChange:(NSNotificationCenter *)notification;
11 {
12 //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）
13 if ([[UIDevice currentDevice] proximityState] == YES)
14 {
15 NSLog(@"Device is close to user");
16 [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
17
18 }
19 else
20 {
21 NSLog(@"Device is not close to user");
22 [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];
23 }
24 }
25
26
27 //初始化播放器的时候如下设置
28 UInt32 sessionCategory = kAudioSessionCategory_MediaPlayback;
29 AudioSessionSetProperty(kAudioSessionProperty_AudioCategory,
30 sizeof(sessionCategory),
31 &sessionCategory);
32
33 UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
34 AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,
35 sizeof (audioRouteOverride),
36 &audioRouteOverride);
37
38 AVAudioSession *audioSession = [AVAudioSession sharedInstance];
39 //默认情况下扬声器播放
40 [audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];
41 [audioSession setActive:YES error:nil];