Android MediaPlayer调用release方法失效 多次播放音频后无法使用如何解决

您好，我按照教程实现MediaPlayer的资源释放逻辑，但释放操作不生效，多次播放音频后就无法再正常使用了，麻烦帮忙排查该如何修复？
我已经将音频raw资源存放在数组中，让MediaPlayer可以为每个列表项播放对应的音频，相关代码如下：

public class NumbersActivity extends AppCompatActivity {

    private MediaPlayer mMediaPlayer;

    private MediaPlayer.OnCompletionListener mOnComplitionListener = new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            releaseMediaPlayer();
        }
    };

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

        final ArrayList<Word> words = new ArrayList<Word>();
        words.add(new Word("one", "lutti", R.drawable.number_one, R.raw.number_one));
        words.add(new Word("two", "otiiko", R.drawable.number_two, R.raw.number_two));
        words.add(new Word("three", "tolookosu", R.drawable.number_three, R.raw.number_three));
        words.add(new Word("four", "oyyisa", R.drawable.number_four, R.raw.number_four));
        words.add(new Word("five", "massokka", R.drawable.number_five, R.raw.number_five));
        words.add(new Word("six", "temmokka", R.drawable.number_six, R.raw.number_six));
        words.add(new Word("seven", "kenekaku", R.drawable.number_seven, R.raw.number_seven));
        words.add(new Word("eight", "kawinta", R.drawable.number_eight, R.raw.number_eight));
        words.add(new Word("nine", "wo'e", R.drawable.number_nine, R.raw.number_nine));
        words.add(new Word("ten", "na'aacha", R.drawable.number_ten, R.raw.number_ten));

        WordAdapter wordAdapter = new WordAdapter(this, words, R.color.category_numbers);
        ListView listView = (ListView) findViewById(R.id.list);
        listView.setAdapter(wordAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
                releaseMediaPlayer();
                Word word = words.get(position);
                MediaPlayer mMediaPlayer = MediaPlayer.create(NumbersActivity.this, word.getmAudio());
                mMediaPlayer.start();
                mMediaPlayer.setOnCompletionListener(mOnComplitionListener);
            }
        });
    }
    private void releaseMediaPlayer() {
        // If the media player is not null, then it may be currently playing a sound.
        if (mMediaPlayer != null) {
            // Regardless of the current state of the media player, release its resources
            // because we no longer need it.
            mMediaPlayer.release();
            // Set the media player back to null. For our code, we've decided that
            // setting the media player to null is an easy way to tell that the media player
            // is not configured to play an audio file at the moment.
            mMediaPlayer = null;
        }
    }
}

问题原因 #

代码在onItemClick方法中重复声明了局部变量mMediaPlayer，导致全局成员变量mMediaPlayer始终为null，releaseMediaPlayer方法从未真正执行资源释放，多次播放后MediaPlayer资源被占满就会无法正常使用。

修复方案 #

将onItemClick方法中的如下代码：
MediaPlayer mMediaPlayer = MediaPlayer.create(NumbersActivity.this, word.getmAudio());
修改为：
mMediaPlayer = MediaPlayer.create(NumbersActivity.this, word.getmAudio());
去掉局部变量声明，直接为全局成员变量赋值即可。

内容的提问来源于stack exchange，提问作者val9