Question

以下是我的 PlayerActivity.java 。它有一个MediaPlayer，它接收从前一个活动流式传输的链接。 MediaPlayer工作正常但当我按下后退按钮或锁定屏幕时，播放器停止。我希望无论正在运行的Activity，甚至屏幕被锁定，都要对音频进行流式传输。

PlayerActivity.java

package com.example.telugump3;

import java.io.IOException;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class PlayerActivity extends Activity {
private Button btn;
String mname;

/**
 * help to toggle between play and pause.
 */
private boolean playPause;
private MediaPlayer mediaPlayer;
/**
 * remain false till media is not completed, inside OnCompletionListener make it true.
 */
private boolean intialStage = true;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Intent iin= getIntent();
    Bundle b = iin.getExtras();


    if(b!=null)
    {
        mname =(String) b.getString("song_link");

    }

    setContentView(R.layout.player_activity);
    btn = (Button) findViewById(R.id.button1);
    mediaPlayer = new MediaPlayer();
    mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
    btn.setOnClickListener(pausePlay);

}


private OnClickListener pausePlay = new OnClickListener() {

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        // TODO Auto-generated method stub


        if (!playPause) {
            btn.setBackgroundResource(R.drawable.button_pause);
            if (intialStage)
                new Player()
                        .execute(mname);


            else {
                if (!mediaPlayer.isPlaying())
                    mediaPlayer.start();

            }
            playPause = true;
        } else {
            btn.setBackgroundResource(R.drawable.button_play);
            if (mediaPlayer.isPlaying())
                mediaPlayer.pause();
            playPause = false;

        }
    }


};
/**
 * preparing mediaplayer will take sometime to buffer the content so prepare it inside the background thread and starting it on UI thread.
 * @author piyush
 *
 */

class Player extends AsyncTask<String, Void, Boolean> {
    private ProgressDialog progress;

    @Override
    protected Boolean doInBackground(String... params) {
        // TODO Auto-generated method stub
        Boolean prepared;
        try {

            mediaPlayer.setDataSource(params[0]);

            mediaPlayer.setOnCompletionListener(new OnCompletionListener() {

                @Override
                public void onCompletion(MediaPlayer mp) {
                    // TODO Auto-generated method stub
                    intialStage = true;
                    playPause=false;
                    btn.setBackgroundResource(R.drawable.button_play);
                    mediaPlayer.stop();
                    mediaPlayer.reset();
                }
            });
            mediaPlayer.prepare();
            prepared = true;
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            Log.d("IllegarArgument", e.getMessage());
            prepared = false;
            e.printStackTrace();
        } catch (SecurityException e) {
            // TODO Auto-generated catch block
            prepared = false;
            e.printStackTrace();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            prepared = false;
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            prepared = false;
            e.printStackTrace();
        }
        return prepared;
    }

    @Override
    protected void onPostExecute(Boolean result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        if (progress.isShowing()) {
            progress.cancel();
        }
        Log.d("Prepared", "//" + result);
        mediaPlayer.start();

        intialStage = false;
    }

    public Player() {
        progress = new ProgressDialog(PlayerActivity.this);
    }

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
        this.progress.setMessage("Buffering...");
        this.progress.show();

    }
}

@Override
protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    if (mediaPlayer != null) {
        mediaPlayer.reset();
        mediaPlayer.release();
        mediaPlayer = null;
    }
}
}

Answer 1

您可以使用Service在后台播放音频。我建议阅读Using a Service with MediaPlayer。

Answer 2

要让它一直播放，请使用Service代替Activity。

如何让我的MediaPlayer活动在后台运行？

2 个答案: