android - SoundManager，如何停止声音播放

Question

我使用简单的SoundManager播放来自sounpool的声音。我的问题是，即使我使用mySound.release();，退出应用程序时声音也不会停止播放。
否则，一切都会正常进行，这是我的代码。

import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;

public class SoundManager {

private Context pContext;
private SoundPool mySound;

private float rate = 1.0f;
private float masterVolume = 1.0f;
private float leftVolume = 1.0f;
private float rightVolume = 1.0f;
private float balance = 0.5f;

// Constructor, setup the audio manager and store the app context
public SoundManager(Context appContext)
{
    mySound = new SoundPool(16, AudioManager.STREAM_MUSIC, 100);

  pContext = appContext;
}

// Load up a sound and return the id
public int load(int sound_id)
{
    return mySound.load(pContext, sound_id, 1);

}


// Play a sound
public void play(int sound_id)
{
    mySound.play(sound_id, leftVolume, rightVolume, 1, 0, rate);    
}   

// Set volume values based on existing balance value
public void setVolume(float vol)
{
    masterVolume = vol;

    if(balance < 1.0f)
    {
        leftVolume = masterVolume;
        rightVolume = masterVolume * balance;
    }
    else
    {
        rightVolume = masterVolume;
        leftVolume = masterVolume * ( 2.0f - balance );
    }

}


public void unloadAll()
{
    mySound.release();      
}

}

Answer 1

方法play()返回int StreamId。您需要将此StreamId保留在变量上并调用stop方法。例如:

声明一个Stream ID变量:

private int mStreamId;

然后，在开始新的声音流时保留它:

// Play a sound
public void play(int sound_id)
{
    mStreamId = mySound.play(sound_id, leftVolume, rightVolume, 1, 0, rate);    
}   

因此，您可以停止它:

mySound.stop(mStreamId);

现在，您可以在 Activity 事件 onStop， onPause或您想要的位置停止声音流。

编辑:

释放 SoundPool资源的最佳方法是调用 release，并在停止播放声音后将引用设置为null。例如:

@Override
protected void onPause() {
    super.onPause();
    mSoundManager.unloadAll();
}

在 SoundManager上，将 unloadAll方法更改为:

public void unloadAll()
{
    mySound.release();
    mySound = null;    
}

Note the following:

onPause – is always called when the activity is about to go into the background.

release: releases all the resources used by the SoundPool

object null: this SoundPool object can no longer be used (like @DanXPrado said) so set it to null to help the Garbage Collector identify it as reclaimable.

有关更多详细信息，请参见 this tutorial about SoundPool。

希望这可以帮助。