android多媒體SoundPool

之前學習過了MediaPlayer用於播放手機音樂，但是在手機中很多的提示音並不是使用MediaPlayer來播放的比如短信鈴聲，通知鈴聲，android中使用SoundPool來播放小的音頻文件；

下面一起學習SoundPool的使用
【1】先搭界面設置一個按鈕用於播放

【2】得到SoundPool

查看API，得知要得到SoundPool根據版本不同有兩種方式
21版本以前使用
SoundPool pool =new SoundPool(int maxStreams, int streamType, int srcQuality)

21版本之後：使用Builder來生成

【3】調用load方法加載音頻

【4】調用play方法
public final int play (int soundID, float leftVolume, float rightVolume, int priority, int loop, float rate)

參數介紹
Parameters
soundID a soundID returned by the load() function
leftVolume left volume value (range = 0.0 to 1.0)左聲道
rightVolume right volume value (range = 0.0 to 1.0)右聲道
priority stream priority (0 = lowest priority)優先級
loop loop mode (0 = no loop, -1 = loop forever)循環與否
rate playback rate (1.0 = normal playback, range 0.5 to 2.0)播放返回的速度

注意事項

如果你的沒有聲音，那是因為加載音頻需要時間，不要把load和play放在一起

下面是源碼

public class MainActivity extends Activity {
    private Button mButton;
    private SoundPool pool = null;
    private int id;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mButton = (Button) findViewById(R.id.button_sound);
        //必須放在外面因為加載音頻需要時間不然會沒有聲音
        id= initSound();
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                playSound();
            }
        });

    }


    private void playSound() {


        //public final int play (int soundID, float leftVolume, float rightVolume, int priority, int loop, float rate)
//         Parameters
//                soundID   a soundID returned by the load() function
//                leftVolume    left volume value (range = 0.0 to 1.0)左聲道
//                rightVolume   right volume value (range = 0.0 to 1.0)右聲道
//                priority  stream priority (0 = lowest priority)優先級
//                loop  loop mode (0 = no loop, -1 = loop forever)循環與否
//                rate  playback rate (1.0 = normal playback, range 0.5 to 2.0)播放返回的速度
        pool.play(id, 1, 1, 0, -1, 1);
    }

    public int initSound() {
        if (Build.VERSION.SDK_INT > 21) {
            SoundPool.Builder builder = new SoundPool.Builder();
            builder.setMaxStreams(2);
            AudioAttributes.Builder builder1 = new AudioAttributes.Builder();
            builder1.setLegacyStreamType(AudioManager.STREAM_MUSIC);
            builder.setAudioAttributes(builder1.build());
            pool = builder.build();

        } else {
            //21版本以前使用SoundPool(int maxStreams, int streamType, int srcQuality)
            pool = new SoundPool(2, AudioManager.STREAM_MUSIC, 0);
        }
        return  pool.load(getApplicationContext(), R.raw.outgoing, 1);

    }
}