今天在做插拔耳麥廣播遇到一個奇怪的現象。本來想把廣播做成全局的，在Manifest文件中配置
<receiver android:name=".receiver.PlayMusicReceiver" android:enabled="true" >
<intent-filter>
<action android:name="android.intent.action.HEADSET_PLUG"/>
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</receiver>結果不給力，插拔耳麥時廣播沒起作用。
木辦法，將廣播接收器寫到某個Activity裏面再試，奇了怪了，還起作用了，爲什麼設成全局的就不起作用呢？
網上搜了一下，下面給出了答案：
However, you need to be aware that HEADSET_PLUG is a "sticky" event, every BroadcastReceiver subscribed to that event will receive it upon construction; I don't know if there is a possibility to determine if the
event has captured at the exact time or been "sticked" for a while.
http://groups.google.com/group/android-developers/browse_thread/thread/6d0dda99b4f42c8f
同時也給出瞭解決方案，將廣播註冊到Service中：
public class PlayMusicService extends Service
{
private final PlayMusicReceiver receiver = new PlayMusicReceiver();
private static final String TAG = "PlayMusicService";
@Override
public IBinder onBind(Intent intent)
{
return null;
}
@Override
public void onCreate()
{
registerReceiver(receiver, new IntentFilter(Intent.ACTION_HEADSET_PLUG));
super.onCreate();
Log.i(TAG, "Create Service");
}
@Override
public void onDestroy()
{
unregisterReceiver(receiver);
super.onDestroy();
Log.i(TAG, "Destroy Service");
}
}