Android Service的用法_e4a添加service

     最近研究了一个android的service，现在做一下总结。

     其实要了解service，我建议不要去到网上看，因为什么呢。网上好多的写的东西都是你抄我，我抄你，都差不多。我建议直接看android的官方文档，只要仔细看了，差不多都能理解，而且官方文档上面还有一些sample。下面我们来一起总结，我打算从以下几个方面来介绍service。

      <serviceandroid:name="com.lee.demo.service.NetworkService">
         <intent-filter>
            <actionandroid:name="com.lee.demo.service.networkservice"/>
            <categoryandroid:name="android.intent.category.default"/>
         </intent-filter>
      </service>

public class NetworkService extends Service
{
       public static final String ACTION_NETWORKSERVICE = "com.lee.demo.service.networkservice";
       private String m_bmpUrl = "http://hiphotos.baidu.com/keyj00/pic/item /816bf9accd05543e4a36d6a6.jpg";
       private ServiceBinder m_serviceBinder = new ServiceBinder();
       private Bitmap m_bitmap = null;
 
       public class ServiceBinder extends Binder implements INetworkService
       {
               @Override
               public Object getData()
               {
                      return m_bitmap;
               }
       }
   
       @Override
       public IBinder onBind(Intent intent)
       {
              return m_serviceBinder;
       }
   
       public void onCreate()
       {
              new Thread(null, new Runnable()
              {
                     @Override
                     public void run()
                     {
                            getBitmapFromNet();
                     }
               }, "GetBitmapFromNetwork").start();
 
              super.onCreate();
       }
   
       protected void getBitmapFromNet()
       {
              m_bitmap = BitmapUtility.getBitmapFromNet(m_bmpUrl);
              if (null != m_bitmap)
              {
                     this.sendBroadcast(new Intent(NetworkReceiver.ACTION_RECEIVER));
              }
       }
       ......
}

public class NetworkActivity extends Activity
{
       // The receiver to recive broadcase from service.
       private NetworkReceiver m_receiver = new NetworkReceiver();
       private INetworkService m_networkService = null;
   
       private ServiceConnection m_serviceConn = new ServiceConnection()
       {
              @Override
              public void onServiceConnected(ComponentName name, IBinder service)
              {
                     // 这里先把这个连接保存起来。
                     m_networkService = (INetworkService)service;           
              }
 
              @Override
              public void onServiceDisconnected(ComponentName name)
              {
              }
       };
   
       public void onCompleteService()
       {
              if (null != m_networkService)
              {
                     // 从Binder中去取数据
                     Bitmap bmp = (Bitmap)m_networkService.getData();
                     if (null != bmp)
                     {
                            // ......
                     }
              }
       }
   
       protected void onCreate(Bundle savedInstanceState)
       {
              super.onCreate(savedInstanceState);
              this.setContentView(R.layout.network_service);
              this.bindService(new Intent(NetworkService.ACTION_NETWORKSERVICE), m_serviceConn, BIND_AUTO_CREATE);
              this.registerReceiver(m_receiver, new IntentFilter(NetworkReceiver.ACTION_RECEIVER));
       }
   
       @Override
       protected void onDestroy()
       {
              this.unbindService(m_serviceConn);
              this.unregisterReceiver(m_receiver);
              super.onDestroy();
       }
}

再看看Receiver如何实现：

public class NetworkReceiver extends BroadcastReceiver
{
 
     public static final String ACTION_RECEIVER ="com.lee.demo.service.networkreceiver";
   
      @Override
      public void onReceive(Context context, Intent intent)
      {
            if (context instanceof NetworkActivity)
             {
                  // 这里调用activity的方法来操作UI的东西。
                  ((NetworkActivity)context).onCompleteService();
            }
      }
}