流式在线广播，主线程工作太多

Question

我正在尝试在一个带有播放和暂停按钮的简单应用中实现在线广播流。我在 onCreate() 方法中做的唯一一件事是在单击按钮时启动和停止服务，当我启动服务时应用程序会抛出一条消息，并且收音机开始缓冲说“应用程序不工作”，带有选项“关闭应用程序/等待”，在 logCat 中它说应用程序在它的主线程上做了太多的工作。我不明白为什么，因为所有艰苦的工作都是在服务中完成的，而不是在 onCreate() 方法中。

我的主要活动：

public class MainActivity extends Activity {

    ImageButton startButton;
    static Context context;
    boolean isPlaying;
    boolean playPause = false;
    Intent streamService;
    SharedPreferences prefs;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context = this;
        AudioManager audio = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        audio.adjustStreamVolume(AudioManager.STREAM_MUSIC,
                AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
        startButton = (ImageButton) findViewById(R.id.music_controls);
        prefs = PreferenceManager.getDefaultSharedPreferences(context);
        getPrefs();
        streamService = new Intent(MainActivity.this, StreamService.class);

        startButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                if (playPause) {
                    stopService(streamService);
                    startButton.setBackgroundDrawable(getResources().getDrawable(R.drawable.ic_play));
                    playPause = false;
                    Log.d("Radio:   ", "Stoping......");
                }else {
                    // TODO Auto-generated method stub

                    Log.d("Radio:   ", "Starting......");
                    startService(streamService);
                    startButton.setBackgroundDrawable(getResources().getDrawable(R.drawable.ic_pause));
                    playPause = true;
                }
            }
        });

    }

    public void onPrepared (MediaPlayer mp){

    }

    public void getPrefs() {
        isPlaying = prefs.getBoolean("isPlaying", false);
        if (isPlaying) playPause = false;
    }

}

我的服务：

public class StreamService extends Service {
    private static final String TAG = "StreamService";
    MediaPlayer mp;
    boolean isPlaying;
    SharedPreferences prefs;
    SharedPreferences.Editor editor;
    Notification n;
    NotificationManager notificationManager;
    // Change this int to some number specifically for this app
    int notifId = 5315;

    @Override
    public IBinder onBind(Intent arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @SuppressWarnings("deprecation")
    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "onCreate");

        // Init the SharedPreferences and Editor
        prefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        editor = prefs.edit();

        // Set up the buffering notification
        notificationManager = (NotificationManager) getApplicationContext()
                .getSystemService(NOTIFICATION_SERVICE);
        Context context = getApplicationContext();

        String notifTitle = context.getResources().getString(R.string.app_name);
        String notifMessage = context.getResources().getString(R.string.buffering);

        n = new Notification();
        n.icon = R.drawable.ic_launcher;
        n.tickerText = "A carregar...";
        n.when = System.currentTimeMillis();

        Intent nIntent = new Intent(context, MainActivity.class);
        PendingIntent pIntent = PendingIntent.getActivity(context, 0, nIntent, 0);

        n.setLatestEventInfo(context, notifTitle, notifMessage, pIntent);

        notificationManager.notify(notifId, n);

        // It's very important that you put the IP/URL of your ShoutCast stream here
        // Otherwise you'll get Webcom Radio
        String url = "My stream url";
        mp = new MediaPlayer();
        mp.setAudioStreamType(AudioManager.STREAM_MUSIC);

        try {
            mp.setDataSource(url);
            mp.prepare();
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SecurityException e) {
            // TODO Auto-generated catch block
            Log.e(TAG, "SecurityException");
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            Log.e(TAG, "IllegalStateException");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            Log.e(TAG, "IOException");
        }
    }

    public int onStartCommand(Intent intent,int flags, int startId) {
        mp.start();
        // Set the isPlaying preference to true
        editor.putBoolean("isPlaying", true);
        editor.commit();

        Context context = getApplicationContext();
        String notifTitle = context.getResources().getString(R.string.app_name);
        String notifMessage = context.getResources().getString(R.string.now_playing);

        n.icon = R.drawable.ic_launcher;
        n.tickerText = notifMessage;
        n.flags = Notification.FLAG_NO_CLEAR;
        n.when = System.currentTimeMillis();

        Intent nIntent = new Intent(context, MainActivity.class);
        PendingIntent pIntent = PendingIntent.getActivity(context, 0, nIntent, 0);

        n.setLatestEventInfo(context, notifTitle, notifMessage, pIntent);
        // Change 5315 to some nother number
        notificationManager.notify(notifId, n);

        return START_STICKY;
    }


    @Override
    public void onDestroy() {
        Log.d(TAG, "onDestroy");
        mp.stop();
        mp.release();
        mp = null;
        editor.putBoolean("isPlaying", false);
        editor.commit();
        notificationManager.cancel(notifId);
    }

}

Answer 1

普通服务确实在主线程上运行。请改用 IntentService。阅读服务http://developer.android.com/reference/android/app/Service.html