音乐的播放与停止

来源：互联网发布：matlab高级编程 pdf 编辑：程序博客网时间：2024/05/01 13:29

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;

public class MainActivity extends Activity {

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

   /* @Override
    public void playMusic(View view) {
    startService(new Intent(this,AudioService.class));
    }*/

    public void playMusic(View view){
    startService(new Intent(this,AudioService.class));//第一个参数为context，第二个参数为要开始的服务类
    }
    public void stopMusic(View view){
    stopService(new Intent(this,AudioService.class));//第一个参数为context，第二个参数为要停止的服务类
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

服务类的内容：

package com.example.service;

/**
* 多线程实现后台播放背景音乐的service
*/
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Binder;
import android.os.IBinder;

public class AudioService extends Service implements
MediaPlayer.OnCompletionListener {
// 实例化MediaPlayer对象
MediaPlayer player;
private final IBinder binder = new AudioBinder();

@Override
public IBinder onBind(Intent intent) {
return binder;
}

public void onCreate() {
  super.onCreate();
  // 从raw文件夹中获取一个应用自带的mp3文件
  player = MediaPlayer.create(this, R.raw.qq);
  player.setOnCompletionListener(this);
  player.setLooping(true);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
  super.onStartCommand(intent, flags, startId);
  if (!player.isPlaying()) {
   new MusicPlayThread().start();
  }
  else player.isPlaying();
  return START_STICKY;
}

/**
* 当Audio播放完的时候触发该动作
*/
public void onCompletion(MediaPlayer mp) {
stopSelf();// 结束了，则结束Service

}

public void onDestroy() {
  super.onDestroy();
  if (player.isPlaying()) {
   player.stop();
  }
  player.release();
}

// 为了和Activity交互，我们需要定义一个Binder对象
public class AudioBinder extends Binder {
  // 返回Service对象
  public AudioService getService() {
   return AudioService.this;
  }
}

private class MusicPlayThread extends Thread {
  public void run() {
   if (!player.isPlaying()) {
    player.start();
   }
  }
}

}

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