Android 判断耳机是否存在
AudioManager就有这个方法:isWiredHeadsetOn()
;
如果插入了耳机,就返回true,否则false;
当然,要加个权限,不然一直是返回false。
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
开始我追了好久的源码。发现了实时检测耳机插入和拔出的过程,不过对我的需求来说帮助不是很大。
实时检测耳机插入和拔出:
每当插入和拔出耳机时,系统都会发送Intent广播,所以,只需要用一个receiver把这个广播intent(获取的action是:“android.intent.action.HEADSET_PLUG”)截获就好。
这个receiver必须要用代码注册,而不能写在manifest里面用写入内存的方式。
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