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");  }}