Question

我正在制作一个包含3个活动的Guitar应用，每个活动都包括一个音频功能，使用SoundPool的原因，并且我有66个样本。我的问题是我必须在每个活动中加载它们，所以我的问题是，有什么方法可以在我的应用启动后立即上传这66个样本，并保持它们在每个活动中加载？

Answer 1

您可以为SoundPool使用一个简单的实用程序类。您可以使用公共静态方法，以便可以实例化一次并从任何活动中对其进行访问。这里是一个可以用于您的案例的类：

import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;
import android.os.Build;
import android.util.Log;

public class SoundPoolManager {
  private static final String TAG = SoundPoolManager.class.getSimpleName();

  private static SoundPool soundPool;
  private static int[] sm;
  private Context context;
  private static float mVolume;

  private static SoundPoolManager instance;
  private static final int SOUND_TOTAL = 1;

  private SoundPoolManager(Context context) {
    this.context = context;
    initSound();

    // add sound here
    // here the sample audio file which can be use with your audio file
    int soundRawId = R.raw.watch_tick;

    //you need to change SOUND_TOTAL for the size of the audio samples.
    sm[sm.length - 1] = soundPool.load(context, soundRawId, 1);
  }

  public static void instantiate(Context context) {
    if(instance == null) instance = new SoundPoolManager(context);
  }

  private void initSound() {
    sm = new int[SOUND_TOTAL];
    int maxStreams = 1;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
      soundPool = new SoundPool.Builder()
          .setMaxStreams(maxStreams)
          .build();
    } else {
      soundPool = new SoundPool(maxStreams, AudioManager.STREAM_MUSIC, 0);
    }
    mVolume = setupVolume(context);
  }

  private float setupVolume(Context context) {
    AudioManager am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
    if(am == null) {
      Log.e(TAG, "Can't access AudioManager!");
      return 0;
    }

    float actualVolume = (float) am.getStreamVolume(AudioManager.STREAM_ALARM);
    float maxVolume = (float) am.getStreamMaxVolume(AudioManager.STREAM_ALARM);

    return actualVolume / maxVolume;
  }

  public static void playSound(int index) {
    if(sm == null) {
      Log.e(TAG, "sm is null, this should not happened!");
      return;
    }

    if(soundPool == null) {
      Log.e(TAG, "SoundPool is null, this should not happened!");
      return;
    }

    if(sm.length <= index) {
      Log.e(TAG, "No sound with index = " + index);
      return;
    }

    if(mVolume > 0) {
      soundPool.play(sm[index], mVolume, mVolume, 1, 0, 1f);
    }
  }

  public static void cleanUp() {
    sm = null;
    if(soundPool != null) {
      soundPool.release();
      soundPool = null;
    }
  }
}

然后您可以在以下类别中使用该类：

// need to call this for the first time
SoundPoolManager.instantiate(context);

// play the sound based on the index
SoundPoolManager.playSound(index);

// clear up the SoundPool when you don't need it anymore.
SoundPoolManager.cleanUp();

在所有活动中保持我的soundPool样本加载

1 个答案: