Question

我有一个接收器，可以在打开或关闭手机屏幕时播放音频。

我将音频文件发送到收件人

                try {
                    Intent i = new Intent("my.action");
                    i.putExtra("posLock", newPosition2).putExtra("songlistLock", mySongs).putExtra("lockSound", "lock");
                    sendBroadcast(i);
                }catch (Exception e) {
                    Log.e(TAG, "Intent error");
                }

和

                try {
                    Intent i = new Intent("my.action.unlock");
                    i.putExtra("posUnlock", newPosition3).putExtra("songlistUnlock", mySongs).putExtra("unlockSound", "unlock");
                    sendBroadcast(i);
                }catch (Exception e) {
                    Log.e(TAG, "Intent error2");
                }

然后我在接收器类上播放音频

LockScreenReceiver.java

public class LockScreenReceiver extends BroadcastReceiver {

MediaPlayer mp;
ArrayList<File> mySongs;
ArrayList<File> mySongs2;
Uri u;
Uri u2;
AudioManager am;
private static final String TAG = SecondScreen.class.getSimpleName();



@Override
public void onReceive(Context context, Intent intent) {

    String action = intent.getAction();
    am = (AudioManager)context.getSystemService(Context.AUDIO_SERVICE);

    if(action.equals("my.action")) {
            Bundle b = intent.getExtras();
            mySongs = (ArrayList) b.getParcelableArrayList("songlistLock");
            int position = b.getInt("posLock", 0);

            u = Uri.parse(mySongs.get(position).toString());
        }

        if(action.equals("my.action.unlock")) {
            Bundle b = intent.getExtras();
            mySongs2 = (ArrayList) b.getParcelableArrayList("songlistUnlock");
            int position = b.getInt("posUnlock", 0);

            u2 = Uri.parse(mySongs2.get(position).toString());
        }


    if (action.equals(Intent.ACTION_SCREEN_ON) && am.getRingerMode() == AudioManager.RINGER_MODE_NORMAL)
    {
        if(u2!=null) {
            stopPlaying();
            mp = MediaPlayer.create(context, u2);
            mp.start();
            Toast.makeText(context, "Audio on playing", Toast.LENGTH_SHORT).show();
        }
    }
    else if (action.equals(Intent.ACTION_SCREEN_OFF) && am.getRingerMode() == AudioManager.RINGER_MODE_NORMAL)
    {
        if(u!=null) {
            stopPlaying();
            mp = MediaPlayer.create(context, u);
            mp.start();
            Toast.makeText(context, "Audio off playing", Toast.LENGTH_SHORT).show();

        }
    }


}

private void stopPlaying() {
    if (mp != null) {
        mp.stop();
        mp.release();
        mp = null;
    }
}
}

我使用服务注册我的接收器

LockScreenService.java

public class LockScreenService extends Service {

BroadcastReceiver receiver;

@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
@SuppressWarnings("deprecation")
public void onCreate() {

    //Start listening for the Screen On, Screen Off, and Boot completed actions
    IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
    filter.addAction(Intent.ACTION_SCREEN_OFF);
    filter.addAction(Intent.ACTION_BOOT_COMPLETED);

    //Set up a receiver to listen for the Intents in this Service
    receiver = new LockScreenReceiver();
    registerReceiver(receiver, filter);
    registerReceiver( receiver, new IntentFilter( "my.action" ) );
    registerReceiver( receiver, new IntentFilter( "my.action.unlock" ) );

   // Toast.makeText(getApplicationContext(), "Starting service now", Toast.LENGTH_SHORT).show();

    super.onCreate();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    return START_STICKY;
}

@Override
public void onDestroy() {
    unregisterReceiver(receiver);
    super.onDestroy();
}
}

我还在我的Manifest.xml中注册我的接收器

的Manifest.xml

    <receiver
        android:name=".LockScreenReceiver"
        android:enabled="true">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
            <action android:name="my.action" />
            <action android:name="my.action.unlock" />
        </intent-filter>
    </receiver>

根据我的阅读，当接收者通过清单注册时，即使应用程序终止，它也应继续运行。但是当我测试它时，在我从最近的应用管理器关闭我的应用后，我的手机停止播放音频。

Answer 1

in.setFlags（Intent.FLAG_RECEIVER_FOREGROUND）;设置此标志然后使用可以在应用程序关闭后运行接收器这也工作在4.4 +。

Answer 2

另一种方式使用可以使用服务然后使用ontaskremoved方法然后使用代码启动新活动然后该活动重启接收器或服务其工作正常如此代码

public void onTaskRemoved(Intent rootIntent)
{

           Intent intent = new Intent(this, DummyActivity.class );
           intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
           startActivity(intent);
           // stopSelf();
           super.onTaskRemoved(rootIntent);     
}

即使应用程序关闭后，接收器也会继续运行

2 个答案: