Android实现检测耳机插入和拔出

在Android下实现检测耳机插入和拔出，也即建立一个Broadcast Receiver，监听“android.intent.action.HEADSET_PLUG”广播

但直接在AndroidManifest.xml中添加一个<receiver>标签是无效的，如：

			<receiver android:name=".HeadsetPlugReceiver">
	          <intent-filter>
	            <action android:name="android.intent.action.HEADSET_PLUG" android:enabled="true"></action>
	          </intent-filter>
	        </receiver> 

你会发现Receiver的onReceive事件永远不会被触发，解决方法就是手动编写代码注册该广播。

首先，创建一个BroadcastReceiver的子类，用于监听耳机插入和拔出：

public class HeadsetPlugReceiver extends BroadcastReceiver {

	private static final String TAG = "HeadsetPlugReceiver";

	@Override
	public void onReceive(Context context, Intent intent) {
		  if (intent.hasExtra("state")){
			   if (intent.getIntExtra("state", 0) == 0){	
				   Toast.makeText(context, "headset not connected", Toast.LENGTH_LONG).show();
			   }
			   else if (intent.getIntExtra("state", 0) == 1){
				   Toast.makeText(context, "headset connected", Toast.LENGTH_LONG).show();
			   }
		  }
		
	}

}

然后，在需要监听该事件的Activity中的onCreate()中注册监听该广播，同时不要忘记在onDestroy()中注销监听该广播：

public class TestHeadSetPlugActivity extends Activity {
	
	private HeadsetPlugReceiver headsetPlugReceiver;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        /* register receiver */
        registerHeadsetPlugReceiver();         
    }

	private void registerHeadsetPlugReceiver() {
		headsetPlugReceiver = new HeadsetPlugReceiver(); 
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("android.intent.action.HEADSET_PLUG");
        registerReceiver(headsetPlugReceiver, intentFilter);
	}
    
    @Override
    public void onDestroy() {
    	unregisterReceiver(headsetPlugReceiver);
    	super.onDestroy();
    }     
}

如上这样就可以实现检测耳机插入和拔出了。

参考：
http://code.google.com/p/android/issues/detail?id=4963

http://groups.google.com/group/android-developers/browse_thread/thread/6d0dda99b4f42c8f/a9c33e446db4f4d1?#a9c33e446db4f4d1