MediaPlayer 不会从其他 class 的方法调用开始

Question

这段代码有一个奇怪的问题，但错误很简单，我不明白。

Class 使用 MediaPlayer 声音和方法：

public class Sounds {

private MediaPlayer stone;
private MediaPlayer gong;

public Sounds(Context con, int stoneSound, int gongSound){
    this.stone = MediaPlayer.create(con, stoneSound);
    this.gong  = MediaPlayer.create(con, gongSound);
}

public void ActivateStone(){
    MediaPlayer auxStone = this.stone;
    auxStone.start(); //THIS IS THE LINE 19 of "Sounds.java:19" log error
    auxStone.setOnCompletionListener(new OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            mp.release();
        }
    });
}

public void ActivateGong(){
    MediaPlayer auxGong = this.gong;
    auxGong.start();
    auxGong.setOnCompletionListener(new OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            mp.release();
        }
    });
}

现在调用方法的线程使用"sound"每个间隔

public void run() {
    while (!stoped) {
        try {
            this.sleep(interval);
            if (stones == mode || stones == (mode * 2)) {
                sounds.ActivateGong();
            } else {
                sounds.ActivateStone(); //THIS IS THE LINE 32 in "Counter.java:32" log error
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        stones += 1;
        handler.setHcron(stones + "");
        handler.act();
    }
}

声音只播放一次，然后应用抛出异常并显示此日志：

05-09 19:10:52.306: E/AndroidRuntime(479): FATAL EXCEPTION: Thread-9448
05-09 19:10:52.306: E/AndroidRuntime(479): Process: contador.piedras.jugger, PID: 479
05-09 19:10:52.306: E/AndroidRuntime(479): java.lang.IllegalStateException
05-09 19:10:52.306: E/AndroidRuntime(479):  at android.media.MediaPlayer._start(Native Method)
05-09 19:10:52.306: E/AndroidRuntime(479):  at android.media.MediaPlayer.start(MediaPlayer.java:1074)
05-09 19:10:52.306: E/AndroidRuntime(479):  at contador.piedras.jugger.Sounds.ActivateStone(Sounds.java:19)
05-09 19:10:52.306: E/AndroidRuntime(479):  at contador.piedras.jugger.Counter.run(Counter.java:32)

Answer 1

也许你应该尝试添加同步，这可能是线程的原因:

    synchronized (auxStone) {
         auxStone.start(); //THIS IS THE LINE 19 of "Sounds.java:19" log error
        auxStone.setOnCompletionListener(new OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mp) {
                mp.release();
            }
        });
    }

编辑： 如文档所述，此方法：抛出： IllegalStateException - 如果它在无效状态下被调用。 所以你需要通过 if(!auxStone.isPlaying())

检查它是否可以播放

MediaPlayer 不会从其他 class 的方法调用开始

MediaPlayer doesn't start with method call from other class

android

media-player