Android Service详解及示例代码

< ?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">
<textview android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="音乐播放服务" android:textsize="25sp" android:layout_margintop="10dp">
<button android:text="开启音乐播放服务" android:textsize="20sp" android:id="@+id/Button01" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margintop="10dp">
</button>
<button android:text="停止音乐播放服务" android:textsize="20sp" android:id="@+id/Button02" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margintop="10dp">
</button>

<button android:text="绑定音乐播放服务" android:textsize="20sp" android:id="@+id/Button03" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margintop="10dp">
</button>
<button android:text="解绑定音乐播放服务" android:textsize="20sp" android:id="@+id/Button04" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margintop="10dp">
</button>
</textview></linearlayout>

package android.basic.lesson14;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

public class MusicService extends Service {

    //为日志工具设置标签
    String tag ="MusicService";    

    //定义音乐播放器变量
    MediaPlayer mPlayer;

    //其他对象通过bindService方法通知该Service时该方法会被调用
    @Override
    public IBinder onBind(Intent intent) {
        Toast.makeText(this,"MusicService onBind()",Toast.LENGTH_SHORT).show();
        Log.i(tag, "MusicService onBind()");
        mPlayer.start();
        return null;
    }

    //其他对象通过unbindService方法通知该Service时该方法会被调用
    @Override
    public boolean onUnbind(Intent intent){
        Toast.makeText(this, "MusicService onUnbind()", Toast.LENGTH_SHORT).show();
        Log.i(tag, "MusicService onUnbind()");
        mPlayer.stop();
        return false;
    }

    //该服务不存在需要被创建时被调用，不管startService()还是bindService()都会在启动时调用该方法
    @Override
    public void onCreate(){
        Toast.makeText(this, "MusicService onCreate()", Toast.LENGTH_SHORT).show();
        //创建一个音乐播放器对象
        mPlayer=MediaPlayer.create(getApplicationContext(), R.raw.babayetu);
        //设置可以重复播放
        mPlayer.setLooping(true);
        Log.i(tag, "MusicService onCreate()");
    }

    //用startService方法调用该服务时，在onCreate()方法调用之后，会调用改方法
    @Override
    public void onStart(Intent intent,int startid){
        Toast.makeText(this,"MusicService onStart",Toast.LENGTH_SHORT).show();
        Log.i(tag, "MusicService onStart()");
        mPlayer.start();
    }

    //该服务被销毁时调用该方法
    @Override
    public void onDestroy(){
        Toast.makeText(this, "MusicService onDestroy()", Toast.LENGTH_SHORT).show();
        mPlayer.stop();
        Log.i(tag, "MusicService onDestroy()");
    }
}

package android.basic.lesson14;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainHelloService extends Activity {

    //为日志工具设置标签
    String tag = "MusicService";

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    //输出Toast消息和日志记录
        Toast.makeText(MainHelloService.this, "MainHelloService onCreate", Toast.LENGTH_SHORT).show();
        Log.i(tag, "MainHelloService onCreate");

    //定义组件对象
    Button b1= (Button)findViewById(R.id.Button01);
    Button b2= (Button)findViewById(R.id.Button02);
    Button b3= (Button)findViewById(R.id.Button03);
    Button b4= (Button)findViewById(R.id.Button04);

     //定义服务链接对象
     final ServiceConnection conn = new ServiceConnection(){

            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                Toast.makeText(MainHelloService.this, "ServiceConnection onServiceConnected", Toast.LENGTH_SHORT).show();
                Log.i(tag, "ServiceConnection onServiceConnected");

            }

            @Override
            public void onServiceDisconnected(ComponentName name) {
                Toast.makeText(MainHelloService.this, "ServiceConnection onServiceDisconnected", Toast.LENGTH_SHORT).show();
                Log.i(tag, "ServiceConnection onServiceDisconnected");

            }};

        //定义点击监听器
    OnClickListener ocl= new OnClickListener(){

            @Override
            public void onClick(View v) {
                //显示指定intent所指的对象是个Service
                Intent intent = new Intent(MainHelloService.this,android.basic.lesson14.MusicService.class);
                switch(v.getId()){
                case R.id.Button01:
                    //开始服务
                    startService(intent);
                    break;
                case R.id.Button02:
                    //停止服务
                    stopService(intent);
                    break;
                case R.id.Button03:
                    //绑定服务
                    bindService(intent,conn,Context.BIND_AUTO_CREATE);
                    break;
                case R.id.Button04:
                    //解除绑定
                    unbindService(conn);
                    break;
                }
            }
    };

    //绑定点击监听器
    b1.setOnClickListener(ocl);
    b2.setOnClickListener(ocl);
    b3.setOnClickListener(ocl);
    b4.setOnClickListener(ocl);  

  }

  @Override
  public void onDestroy(){
      super.onDestroy();
        Toast.makeText(MainHelloService.this, "MainHelloService onDestroy", Toast.LENGTH_SHORT).show();
        Log.i(tag, "MainHelloService onDestroy");
  }
}