java - 在 MediaPlayer 中连续播放声音时应用程序崩溃

Question

我找到了以下代码作为此处问题的答案 Playing multiple files in MediaPlayer one after other In android

当我运行它时，会播放 3 种声音，但随后应用会关闭并显示消息

unfortunately the application has stopped.

onCompletion 方法中是否缺少某些内容？

public class MainActivity extends Activity implements MediaPlayer.OnCompletionListener {

    int[] tracks = new int[3];
    int currentTrack = 0;
    private MediaPlayer mediaPlayer = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tracks[0] = R.raw.p46;
        tracks[1] = R.raw.p52;
        tracks[2] = R.raw.p55;
        mediaPlayer = MediaPlayer.create(getApplicationContext(), tracks[currentTrack]);
        mediaPlayer.setOnCompletionListener(this);
        mediaPlayer.start();
    }

    public void onCompletion(MediaPlayer arg0) {
        arg0.release();
        if (currentTrack < tracks.length) {
            currentTrack++;
            arg0 = MediaPlayer.create(getApplicationContext(), tracks[currentTrack]);
            arg0.setOnCompletionListener(this);
            arg0.start();
        }
    }

Answer 1

改变这个:

public void onCompletion(MediaPlayer arg0) {
        arg0.release();
        if (currentTrack < tracks.length) {
            currentTrack++;
            arg0 = MediaPlayer.create(getApplicationContext(), tracks[currentTrack]);
            arg0.setOnCompletionListener(this);
            arg0.start();
        }
    }

到:

public void onCompletion(MediaPlayer arg0) {
        arg0.release();
        currentTrack++;
        if (currentTrack < tracks.length) {

            arg0 = MediaPlayer.create(getApplicationContext(), tracks[currentTrack]);
            arg0.setOnCompletionListener(this);
            arg0.start();
        }
    }

基本上你会得到一个 ArrayIndexOutofBoundException 因为最后 currentTrack 是 3 并且在索引 3 处没有项目，即第 4 项