Android编程心得-Service数据绑定初步

1.首先我们要定义一个接口，接口里定义我们需要实现的方法

public interface ICount {
public int getcount();

}

2.接下来我们需要一个Service的子类实现本接口，定义一个ServiceBinder的内部类，通过它的对象来绑定数据，要注意的是我们如果要进行耗时操作的话，仍然需要在Service中创建线程，Service自身就是运行在主线程中的。还有一个就是OnBind的返回值是IBinder,但是这里我使用ServiceBinder对象是继承Binder的，那为什么这里可以这么写呢？因为Binder是Base
class for a remotable object, the core part of a lightweight remote procedure call mechanism defined by

IBinder，是直接从IBinder这里的直接子类

。

public class BackGroundService extends Service implements ICount {
private boolean disable;  //线程是否执行的标识位
private int count;      //计数
private ServiceBinder serviceBinder = new ServiceBinder();

public class ServiceBinder extends Binder implements ICount {
@Override
public int getcount() {
// TODO Auto-generated method stub
return 0;
}
}

@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return serviceBinder;
}

@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
new Thread(new Runnable() {
// @Override
public void run() {
while (!disable) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
count++;
System.out.println("CountService Count is " + count);
}
}
}).start();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Auto-generated method stub

return super.onStartCommand(intent, flags, startId);
}

@Override
public int getcount() {
return count;
// TODO Auto-generated method stub

}

@Override
public void onDestroy() {
// TODO Auto-generated method stub
this.disable = true;
//		Log.v(" CountService ", " on destroy ");
System.out.println("Service destroy...");
super.onDestroy();
}

}

3.定义完了Service这一部分的内容，接下来就需要在AndroidManifest.xml中注册了，需要注意的是这里不仅要对我们包类的Service进行声明，同时还需要声明intent的过滤器

<service android:name="com.yqc.testservice.BackGroundService">
<intent-filter>
<action android:name="com.yqc.testservice.BackGroundService" />
</intent-filter>
</service>

4.定义完毕以后，接下来需要在Activity中的交互部分了，刚才在配置文件中定义的Intent的过滤器这里就用到了，在bindService方法中，这就是他的一个参数，然后通过ServiceConnetion的对象与Service建立连接并取得后台的参数。

public class MainActivity extends Activity {

Button btn_start;

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

this.bindService(new Intent("com.yqc.testservice.BackGroundService"),
this.serviceConnection, BIND_AUTO_CREATE);

btn_start = (Button) findViewById(R.id.btn_start);
btn_start.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub

}
});
}

@Override
protected void onDestroy() {
// TODO Auto-generated method stub
this.unbindService(serviceConnection);
System.out.println("Activity Destroy...");
super.onDestroy();
}

private ICount countentity;

private ServiceConnection serviceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
// TODO Auto-generated method stub
countentity = (ICount) service;
System.out.println(" CountService on serivce connected, count is "
+ countentity.getcount());
}

@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub
countentity = null;
}
};
}

5.最后得到的结果如下