Android：MediaPlayer 问题 Class，无法播放歌曲

Question

这段代码有什么问题，因为没有播放音乐？
这是一首mp3文件格式的歌曲，大小为4兆res/raw。

public class MainActivity extends AppCompatActivity {
  MediaPlayer mediaPlayer = new MediaPlayer();

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

    mediaPlayer.create(MainActivity.this, R.raw.music);

    ((Button)findViewById(R.id.playButton)).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
          mediaPlayer.start();
          Toast.makeText(MainActivity.this, "Play", Toast.LENGTH_SHORT).show();
        }
    });

    ((Button)findViewById(R.id.pauseButton)).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
          mediaPlayer.pause();
          Toast.makeText(MainActivity.this, "Pause", Toast.LENGTH_SHORT).show();
        }
    });
  }
}

Answer 1

在OnCreate()

中初始化

public class MainActivity extends AppCompatActivity {
MediaPlayer mediaPlayer;

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

    mediaPlayer =  MediaPlayer.create(MainActivity.this, R.raw.music);

    //...
  }
}

Answer 2

// assign the instance to mediaPlayer object

mediaPlayer =  MediaPlayer.create(MainActivity.this, R.raw.music);

Android：MediaPlayer 问题 Class，无法播放歌曲

Android: Problems with MediaPlayer Class, not play a song

android

android-mediaplayer