音乐的播放与停止


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();

   }

  }

 }

  

}