在不同类中播放声音类Android

Question

我在另一个类中从我的SoundManager类调用方法时遇到了一些麻烦。这是SoundManager类。

公共类SoundManager类{

private SoundPool soundPool; 
public static final int maxSounds = 2; 
AudioManager audioManager; 
private int[] soundId; 
private Context context; //= mGame.getActivity().getApplicationContext(); 
Game mGame; 
public SoundManager(Game game) { 
    super(); 
    context = game.getActivity().getApplicationContext(); 
    //this.mGame = game; 

    soundPool = new SoundPool(maxSounds, AudioManager.STREAM_MUSIC, 0); 

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { 
     soundPool = new SoundPool.Builder() 
       .setMaxStreams(maxSounds) 
       .build(); 
    } else { 
     soundPool = new SoundPool(maxSounds, AudioManager.STREAM_MUSIC, 0); 
    } 

    soundId = new int[16]; 

    soundId[0] = soundPool.load(context, R.raw.sound1, 1); 
    //soundId[1] = soundPool.load(context, R.raw.cardsound, 1); 
    soundId[2] = soundPool.load(context, R.raw.swoosh, 1); 
    soundId[3] = soundPool.load(context, R.raw.clicksound, 1); 
    soundId[4] = soundPool.load(context, R.raw.scifi, 1); 
    soundId[5] = soundPool.load(context, R.raw.phasebattle, 1); 
    soundId[6] = soundPool.load(context, R.raw.card_mr_electron, 1); 
    soundId[7] = soundPool.load(context, R.raw.card_james_watt, 1); 
    soundId[8] = soundPool.load(context, R.raw.card_marvin, 1); 
    soundId[9] = soundPool.load(context, R.raw.card_leonardo, 1); 
    soundId[10] = soundPool.load(context, R.raw.card_edmund, 1); 
    soundId[11] = soundPool.load(context, R.raw.card_terminator, 1); 
    soundId[12] = soundPool.load(context, R.raw.card_mr_robot, 1); 
    soundId[13] = soundPool.load(context, R.raw.card_labrat, 1); 
    soundId[14] = soundPool.load(context, R.raw.card_nerd, 1); 
    soundId[15] = soundPool.load(context, R.raw.card_angle, 1); 

    audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE); 
} 

public void playSound(int sound, float volume) { 
    soundPool.play(soundId[sound], volume, volume, 1, 0, 1f); 
} 

而这里就是我想称之为第二类的一部分。当我去运行应用程序时，堆栈跟踪将我恢复到SoundManager中用于初始化上下文的行，并指出.getActivity（）无法在空对象引用上初始化。

公共类播放器{

private GameScreen mGameScreen; 

private Game mGame; 
SoundManager mSoundManager = new SoundManager(mGame); 

public Player(GameScreen gameScreen, GameEventHandler mGameEventHandler, Game game) { 
    super(); 

} 

Answer 1

当初始化SoundManager，Game尚不存在。

试试这个：

public class Player { 

private GameScreen mGameScreen; 

    private Game mGame; 
    SoundManager mSoundManager; 

    public Player(GameScreen gameScreen, GameEventHandler mGameEventHandler, Game game) { 
      super(); 
      mSoundManager = new SoundManager(game) 

    } 
    . 
    .