iOS 监测耳机连接状态

首先要添加 #import <AVFoundation/AVFoundation.h>头文件。

//注册通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(outputDeviceChanged:) name:AVAudioSessionRouteChangeNotification object:[AVAudioSession sharedInstance]];
//实现
- (void)outputDeviceChanged:(NSNotification *)aNotification
{
    // do your jobs here    
}