跨多种活动的Android全面防故障音乐服务

Question

我知道这个问题已经被问了很多次,可能似乎是几个问题堆集,但我觉得这是相关的,重要的是许多开发人员; 我需要Service为我的Android游戏创建一个可以运行多个活动的背景音乐,这些活动在应用程序终止时结束,并在以下所有情况下暂停:

1. 一个Activity有自己音乐的东西就开始了.(Activity完成时完成.这恰好是一项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TelephonyManager类似于此.
4. 屏幕已锁定.(简历屏已经被解锁后)需要使用的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.

我发现很奇怪,AndEngine他们的音乐没有这些问题,所以也许查看源代码可以帮助寻找答案的人.我正在使用Google Code的最新功能GLES1版本.

我已经看过以下链接以及创建好音乐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:

• BroadcastReceivers尽可能减少使用和Android Manifest添加/权限的最小化
• 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();