跨多种活动的Android全面防故障音乐服务

Question

我知道这个问题之前已被问过很多次，似乎是几个问题的集合，但我觉得这对很多开发人员来说都很重要; 我需要创建一个背景音乐Service ，它可以运行我的Android游戏的多个活动，在应用程序终止时结束，并在以下所有情况下暂停：

1. 已启动具有自己音乐的某个Activity 。 （在此Activity完成时恢复。这恰好是AndEngine活动。）
2. 按下主屏幕，应用程序背景，或终止应用程序。 应用程序返回前台时恢复。 需要使用onUserLeaveHint() 。 另一个有用的链接
3. 手机接到电话并中断应用程序。 处理呼叫时恢复。 需要使用类似于此的TelephonyManager 。
4. 屏幕已锁定。 （简历屏已经被解锁后）需要使用ACTION_USER_PRESENT ，这似乎是 非常 有问题的 。
5. 基本上，只要没有显示应用程序或者向用户显示来自＃1的特殊活动，音乐就会暂停。

以上是我需要的所有内容以及我拼凑在一起的信息。 我目前的代码基本上类似于此 。

我发现AndEngine设法在他们的音乐中没有AndEngine这些问题，这很奇怪，所以查看源代码可能有助于寻找答案的人。 我正在使用Google Code的最新功能GLES1版本 。

我已经看了以下链接以及创建一个好的音乐Service ：

• 停止背景服务音乐
• http://www.codeproject.com/Articles/258176/Adding-Background-Music-to-Android-App
• Android背景音乐服务
• 在Android中播放BG音乐
• http://www.rbgrn.net/content/307-light-racer-20-days-61-64-completion

我想解决方案Service ：

• 尽可能减少BroadcastReceivers和Android Manifest添加/权限的使用
• 自包含和错误检查

其他说明

• 目前，所有需要背景音乐的活动都扩展了一个共同的特殊课程。
• 音乐需要循环，但只运行一个轨道。

提前感谢大家！ 祝你好运！

编辑 - 这是代码片段，随意改进或忽略：

媒体播放器包装

import android.content.SharedPreferences;
import android.media.MediaPlayer;
import android.preference.PreferenceManager;
import android.util.Log;

public class CarefulMediaPlayer {
    final SharedPreferences sp;
    final MediaPlayer mp;
    private boolean isPlaying = false;

    public CarefulMediaPlayer(final MediaPlayer mp, final MusicService ms) {
        sp = PreferenceManager.getDefaultSharedPreferences(ms.getApplicationContext());
        this.mp = mp;
    }

    public void start() {
        if (sp.getBoolean("com.embed.candy.music", true) && !isPlaying) {
            mp.start();
            isPlaying = true;
        }
    }

    public void pause() {
        if (isPlaying) {
            mp.pause();
            isPlaying = false;
        }
    }

    public void stop() {
        isPlaying = false;
        try {
            mp.stop();
            mp.release();
        } catch (final Exception e) {}
    }
}

音乐服务

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;

public class MusicService extends Service {
    static CarefulMediaPlayer mPlayer = null;

    @Override
    public IBinder onBind(final Intent arg0) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        final MediaPlayer mp = MediaPlayer.create(this, R.raw.title_music);
        mp.setLooping(true);
        mPlayer = new CarefulMediaPlayer(mp,this);
    }

    @Override
    public int onStartCommand(final Intent intent, final int flags, final int startId) {
        mPlayer.start();
        return 1;
    }

    @Override
    public void onStart(final Intent intent, final int startId) {

    }

    public IBinder onUnBind(final Intent arg0) {
        return null;
    }

    public static void onStop() {
        mPlayer.stop();
    }

    public static void onPause() {
        if (mPlayer!=null) {
            mPlayer.pause();
        }
    }

    public static void onResume() {
        if (mPlayer!=null) {
            mPlayer.start();
        }
    }

    @Override
    public void onDestroy() {
        mPlayer.stop();
        mPlayer = null;
    }

    @Override
    public void onLowMemory() {

    }
}

改进的基本活动类

import android.app.Activity;
import android.content.Intent;
import android.os.PowerManager;
import android.telephony.TelephonyManager;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;

public abstract class BetterActivity extends Activity {

    private boolean isHome = true;

    @Override
    protected void onResume() {
        System.gc();
        super.onResume();
        MusicService.onResume();
        isHome = true;
    }

    @Override
    protected void onPause() {
        if (((TelephonyManager)getSystemService(TELEPHONY_SERVICE)).getCallState()==TelephonyManager.CALL_STATE_RINGING
                || !((PowerManager)getSystemService(POWER_SERVICE)).isScreenOn()) {
            MusicService.onPause();
        }
        super.onPause();
        System.gc();
    }

    @Override
    public boolean onKeyDown (final int keyCode, final KeyEvent ke) {
        switch (keyCode) {
        case KeyEvent.KEYCODE_BACK:
            isHome = false;
        default:
            return super.onKeyDown(keyCode, ke);
        }
    }

    @Override
    public void startActivity(final Intent i) {
        isHome = false;
        super.startActivity(i);
    }

    @Override
    protected void onUserLeaveHint() {
        if (isHome) {
            MusicService.onPause();
        }
        super.onUserLeaveHint();
    }

}

Answer 1

首先是一些代码。 下面我会给你一个解释。

public class MusicService extends Service {

    // service binder
    private final IBinder mBinder = new LocalBinder();

    // music player controling game music
    private static CarefulMediaPlayer mPlayer = null;

    @Override
    public void onCreate() {
        // load music file and create player
        MediaPlayer mediaPlayer = MediaPlayer.create(this, R.raw.title_music);
        mediaPlayer.setLooping(true);
        mPlayer = new CarefulMediaPlayer(mediaPlayer, this);
    }

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

    // =========================
    // Player methods
    // =========================
    public void musicStart() {
        mPlayer.start();
    }

    public void musicStop() {
        mPlayer.stop();
    }

    public void musicPause() {
        mPlayer.pause();
    }

    /**
     * Class for clients to access. Because we know this service always runs in
     * the same process as its clients, we don't need to deal with IPC.
     */
    public class LocalBinder extends Binder {
        MusicService getService() {
            return MusicService.this;
        }
    }

    @Override
    public IBinder onBind(Intent arg0) {
        return mBinder;
    }

}

活动：

public class StartupActivity extends Activity {

// bounded service
private static MusicService mBoundService;

// whetere service is bounded or not
private boolean mIsBound;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_startup);
    doBindService();

    // HOW TO WORK WITH THE SERVICE:
    // call the following methods whenever
    // you want to interact with you 
    // music player
    // ===================================

    // call this e.g. in onPause() of your Activities
    StartupActivity.getService().musicPause();

    // call this e.g. in onStop() of your Activities
    StartupActivity.getService().musicStop();

    // call this e.g. in onResume() of your Activities
    StartupActivity.getService().musicStart();
}

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

private final ServiceConnection mServiceConnection = new ServiceConnection() {

    @Override
    public void onServiceConnected(ComponentName className, IBinder service) {
        setService(((MusicService.LocalBinder) service).getService());
    }

    @Override
    public void onServiceDisconnected(ComponentName className) {
        setService(null);
    }
};

private void doBindService() {
    Intent service = new Intent(getBaseContext(), MusicService.class);
    // start service and bound it
    startService(service);
    bindService(new Intent(this, MusicService.class), mServiceConnection, Context.BIND_AUTO_CREATE);
    mIsBound = true;
}

private void doUnbindService() {
    if (mIsBound) {
        // Detach existing connection.
        unbindService(mServiceConnection);
        mIsBound = false;
    }
}

public static MusicService getService() {
    return mBoundService;
}

private static void setService(MusicService mBoundService) {
    StartupActivity.mBoundService = mBoundService;
}
}

首先，你有一个在后台运行的服务。 此服务像您一样创建mediaPlayer对象。 使用localBinder，您可以在Activity中绑定Service，并像普通的Java-Object一样访问它。 我发布的活动bindes the Service。 在它的onCreate（）方法中，您可以找到一种如何与您的mediaPlayer进行交互的方法。 您可以将任何活动绑定到您的服务。

另一种方案：

public class CarefulMediaPlayer {
final SharedPreferences sp;
final MediaPlayer mp;
private boolean isPlaying = false;
private static CarefulMediaPlayer instance;

public CarefulMediaPlayer(final MediaPlayer mp, final MusicService ms) {
    sp = PreferenceManager.getDefaultSharedPreferences(ms.getApplicationContext());
    this.mp = mp;
    instance = this;
}

public static CarefulMediaPlayer getInstance() {
    return instance;
}

public void start() {
    if (sp.getBoolean("com.embed.candy.music", true) && !isPlaying) {
        mp.start();
        isPlaying = true;
    }
}

public void pause() {
    if (isPlaying) {
        mp.pause();
        isPlaying = false;
    }
}

public void stop() {
    isPlaying = false;
    try {
        mp.stop();
        mp.release();
    } catch (final Exception e) {}
}
}

然后你可以通过调用CarefulMediaPlayer.getInstance（）来暂停，播放和停止音乐.play（）;

Answer 2

我是这样做的，我很满意结果：

1创建服务：

public class LocalService extends Service
{
    // This is the object that receives interactions from clients. See RemoteService for a more complete example.
    private final IBinder mBinder = new LocalBinder();
    private MediaPlayer player;

    /**
     * Class for clients to access. Because we know this service always runs in
     * the same process as its clients, we don't need to deal with IPC.
     */
    public class LocalBinder extends Binder
    {
        LocalService getService()
        {
            return LocalService.this;
        }
    }

    @Override
    public void onCreate()
    {

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        // We want this service to continue running until it is explicitly stopped, so return sticky.
        return START_STICKY;
    }

    @Override
    public void onDestroy()
    {
        destroy();
    }

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


    public void play(int res)
    {
        try
        {
            player = MediaPlayer.create(this, res);
            player.setLooping(true);
            player.setVolume(0.1f, 0.1f);
            player.start();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }


    public void pause()
    {
        if(null != player && player.isPlaying())
        {
            player.pause();
            player.seekTo(0);
        }
    }


    public void resume()
    {
        try
        {
            if(null != player && !player.isPlaying())
            {
                player.start();
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }


    public void destroy()
    {
        if(null != player)
        {
            if(player.isPlaying())
            {
                player.stop();
            }

            player.release();
            player = null;
        }
    }

}

2 ，创建一个基础活动并扩展您希望播放背景音乐的所有活动：

public class ActivityBase extends Activity
{
    private Context context = ActivityBase.this;
    private final int [] background_sound = { R.raw.azilum_2, R.raw.bg_sound_5 };
    private LocalService mBoundService;
    private boolean mIsBound = false;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        doBindService();
    }

    @Override
    protected void onStart()
    {
        super.onStart();

        try
        {
            if(null != mBoundService)
            {
                Random rand = new Random();
                int what = background_sound[rand.nextInt(background_sound.length)];
                mBoundService.play(what);
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

    @Override
    protected void onStop()
    {
        super.onStop();
        basePause();
    }



    protected void baseResume()
    {
        try
        {
            if(null != mBoundService)
            {
                mBoundService.resume();
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }


    protected void basePause()
    {
        try
        {
            if(null != mBoundService)
            {
                mBoundService.pause();
            }
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }



    private ServiceConnection mConnection = new ServiceConnection()
    {
        public void onServiceConnected(ComponentName className, IBinder service)
        {
            // This is called when the connection with the service has been
            // established, giving us the service object we can use to
            // interact with the service. Because we have bound to a explicit
            // service that we know is running in our own process, we can
            // cast its IBinder to a concrete class and directly access it.
            mBoundService = ((LocalService.LocalBinder) service).getService();

            if(null != mBoundService)
            {
                Random rand = new Random();
                int what = background_sound[rand.nextInt(background_sound.length)];
                mBoundService.play(what);
            }
        }

        public void onServiceDisconnected(ComponentName className)
        {
            // This is called when the connection with the service has been
            // unexpectedly disconnected -- that is, its process crashed.
            // Because it is running in our same process, we should never
            // see this happen.
            mBoundService = null;

            if(null != mBoundService)
            {
                mBoundService.destroy();
            }
        }
    };

    private void doBindService()
    {
        // Establish a connection with the service. We use an explicit
        // class name because we want a specific service implementation that
        // we know will be running in our own process (and thus won't be
        // supporting component replacement by other applications).

        Intent i = new Intent(getApplicationContext(), LocalService.class);
        bindService(i, mConnection, Context.BIND_AUTO_CREATE);
        mIsBound = true;
    }

    private void doUnbindService()
    {
        if (mIsBound)
        {
            // Detach our existing connection.
            unbindService(mConnection);
            mIsBound = false;
        }
    }


    @Override
    protected void onDestroy()
    {
        super.onDestroy();
        doUnbindService();
    }
}

就是这样，现在您在从ActivityBase扩展的所有活动中都有背景声音。

您甚至可以通过调用basePause（）/ baseResume（）来控制暂停/恢复功能。

不要忘记在清单中声明服务：

<service android:name="com.gga.screaming.speech.LocalService" />

Answer 3

在启动活动中，我们分别绑定和启动服务。 这是错误的，因为服务将在活动退出后继续运行，因为我们没有在任何地方调用stopService（） 。 所以应该删除部分'startService（service）'，因为绑定服务已经“ 自动创建 ”了服务。

如果有人得到相反的结果，请纠正我

startService(service);// remove this part
bindService(new Intent(this, MusicService.class), mServiceConnection, Context.BIND_AUTO_CREATE);