实时监听耳机拔除

当用户正在使用咱们产品里提供的音乐播放器播放音乐时，用户把耳机或者蓝牙耳机接入后，过一下子，用户又把耳机给拔除，或者断开蓝牙耳机的链接，咱们须要暂停播放音乐，定义一个BroadcastReceiver对象，  对于有线耳机，监听Intent.ACTION_HEADSET_PLUG系统广播，对于蓝牙耳机，监听BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED系统广播

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private void registerHeadsetPlugReceiver() {            IntentFilter intentFilter = new IntentFilter();            intentFilter.addAction("android.intent.action.HEADSET_PLUG");            registerReceiver(headsetPlugReceiver, intentFilter);                       // for bluetooth headset connection receiver          IntentFilter bluetoothFilter = new IntentFilter(BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED);          registerReceiver(headsetPlugReceiver, bluetoothFilter);      }              private BroadcastReceiver headsetPlugReceiver = new BroadcastReceiver() {              @Override          public void onReceive(Context context, Intent intent) {                              String action = intent.getAction();              if (BluetoothHeadset.ACTION_CONNECTION_STATE_CHANGED.equals(action)) {                  BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();                  if(BluetoothProfile.STATE_DISCONNECTED == adapter.getProfileConnectionState(BluetoothProfile.HEADSET)) {                      //Bluetooth headset is now disconnected                      handleHeadsetDisconnected();                  }              } else if ("android.intent.action.HEADSET_PLUG".equals(action)) {                  if (intent.hasExtra("state")) {                      if (intent.getIntExtra("state", 0) == 0) {                          handleHeadsetDisconnected();                      }                  }              }          }                  };

 这样作能够基本知足需求，但不完美，由于当拔出有线耳机时，播放器不会立刻暂停，要等上一秒钟，才会收到Android的系统广播，

1	android.intent.action.HEADSET_PLUG，他说其余音乐播放器没有这个延迟，通过调查发现，QQ音乐确实没有这个延迟，耳机一拔，播放器马上暂停，

 

相关资料：从硬件层面来看，直接监听耳机拔出事件不难，耳机的拔出和插入，会引发手机电平的变化，而后触发什么什么中断，

最终在stack overflow找到答案，监听Android的系统广播AudioManager.ACTION_AUDIO_BECOMING_NOISY， 可是这个广播只是针对有线耳机，或者无线耳机的手机断开链接的事件，监听不到有线耳机和蓝牙耳机的接入，但对于个人需求来讲足够了，监听这个广播就没有延迟了，UI能够当即响应

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private void registerHeadsetPlugReceiver() {            IntentFilter intentFilter = new IntentFilter(AudioManager.ACTION_AUDIO_BECOMING_NOISY);            registerReceiver(headsetPlugReceiver, intentFilter);       }              private BroadcastReceiver headsetPlugReceiver = new BroadcastReceiver() {              @Override          public void onReceive(Context context, Intent intent) {              String action = intent.getAction();              if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(action)) {                  handleHeadsetDisconnected();              }          }                  };