Question

我使用asyncTask完成了以下代码，用于在活动背景中运行音乐。

 public class BackgroundSound extends AsyncTask<Void, Void, Void>
 {
  @Override
  protected Void doInBackground(Void... params) 
    {    MediaPlayer player = MediaPlayer.create(BiographyActivity.this, R.raw.test_cbr); 
  player.setLooping(true); // Set looping 
  player.setVolume(100,100); 
      player.start(); 
      return null;      }
  }


@Override
protected void onResume() 
{ super.onResume();
  mBackgroundSound.execute(null); }


@Override
protected  void onPause()
  {  super.onPause();
    mBackgroundSound.cancel(true);   }

但它在onResume：

中的执行方法显示错误

The method execute(Void[]) is ambiguous for the type BiographyActivity.BackgroundSound

Answer 1

我强烈建议您不要使用异步任务来播放背景音乐，而是可以使用媒体播放器类中的prepareAsync方法，该方法本身会在后台加载音乐。

以下是我的实施：

import java.io.IOException;

import android.app.Activity;
import android.content.res.AssetFileDescriptor;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;

public class BiographyActivity extends Activity implements OnPreparedListener {

private MediaPlayer mMediaPlayer;

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

@Override
protected void onResume() {
    super.onResume();
    final AssetFileDescriptor afd = getResources().openRawResourceFd(R.raw.test);
    try {
        releaseMediaPlayer();
        mMediaPlayer = new MediaPlayer();
        mMediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getDeclaredLength());
        mMediaPlayer.setOnPreparedListener(this);
        mMediaPlayer.prepareAsync();
        afd.close();
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

@Override
protected void onPause() {
    super.onPause();
    releaseMediaPlayer();
}

private void releaseMediaPlayer() {
    if (mMediaPlayer != null && mMediaPlayer.isPlaying()) {
        mMediaPlayer.stop();
        mMediaPlayer.reset();
        mMediaPlayer.release();
    }
}

@Override
public void onPrepared(MediaPlayer mp) {
    mp.start();
}
}

Answer 2

这意味着View []不明确，尝试执行（Void [3]）或执行（）;

尝试在AsyncTask中运行mediaPlayer时显示错误

2 个答案: