Android開發之Service與Activity數據交互（源代碼分享）

Service想要與Activity進行數據交互，首先Activity先得綁定Service.bound service是service 的實現,它允許其他應用程序綁定到它並與之交互。要提供bound service,我們必須實現onBind()回調方法。這個方法返回一個內部對象定義的編程接口,Activity可以使用與Service進行交互。那麼具體該如何實現呢，首先我們還是一樣先創建一個MyService繼承Service。然後如何設置:呢。（1）在你的Service,創建一個Binder實例,返回當前的Service實例以及一個Activity可以調用公共方法。（2）返回這個實例的Binder在onBind()回調方法。（3）在Activity裡創建ServiceConnection,在onServiceConnected()回調方法接受Binder,並得到服務器的實例。講的比較啰嗦哦，我們還是看代碼來細細品味吧。

Service的代碼

package com.example.f22_service02;

import java.util.Random;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.os.Parcel;
import android.os.RemoteException;
import android.util.Log;

public class HelloService extends Service {
    private MyBinder binder=new MyBinder();
	
	public class MyBinder extends Binder{
		public HelloService getService(){
			return HelloService.this;  
			//返回Service實例，使主程序能調用該方法
	  
		}
		@Override
		protected boolean onTransact(int code, Parcel data, Parcel reply,
				int flags) throws RemoteException {
			// TODO Auto-generated method stub
			Log.i("TAG", "------>"+data.readInt());
			Log.i("TAG", "------>"+data.readString());
			reply.writeInt(2);
			reply.writeString("Rose");
			return super.onTransact(code, data, reply, flags);
		}
		
	}
	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return binder; //回掉方法
	}
	public int getRandom(){
		return new Random().nextInt(100);
		
	}
	
	
	@Override
	public void onCreate() {
		// TODO Auto-generated method stub
		Log.i("TAG", "------>Create");
		super.onCreate();
		
	}
	@Override
	public boolean onUnbind(Intent intent) {
		// TODO Auto-generated method stub
		Log.i("TAG", "------>Unbind");
		return super.onUnbind(intent);
	}

}

package com.example.f22_service02;

import com.example.f22_service02.HelloService.MyBinder;

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

@SuppressLint("Recycle")
public class MainActivity extends Activity implements OnClickListener {
	private Button button, button2, button3;
	private MyBinder binder;
	private HelloService helloService;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		button = (Button) this.findViewById(R.id.button1);
		button2 = (Button) this.findViewById(R.id.button2);
		button3 = (Button) this.findViewById(R.id.button3);
		button.setOnClickListener(this);
		button2.setOnClickListener(this);
		button3.setOnClickListener(this);
	}


	private ServiceConnection connection = new ServiceConnection() {

		@Override
		public void onServiceDisconnected(ComponentName name) {
			// TODO Auto-generated method stub
			
			Log.i("ACTIVITY", "---------〉失去綁定");
		
		}

		@Override
		public void onServiceConnected(ComponentName name, IBinder service) {
			// TODO Auto-generated method stub
			binder = (MyBinder) service; // 綁定Service，並獲得Service實例，接下來就可以調用Service中的方法了
			helloService = binder.getService();
			
			Log.i("ACTIVITY", "---------〉綁定成功");
		}
	};
	@SuppressLint("Recycle")
	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		switch (v.getId()) {
		case R.id.button1:
            //綁定Service
			Intent intent=new Intent(MainActivity.this,HelloService.class);
			bindService(intent, connection, Context.BIND_AUTO_CREATE);//第三個參數是一個標志顯示選項綁定
		
			break;

		case R.id.button2:
			//實現Activity與Service的數據交互
			//Parcel是一個容器，能包含消息(數據和對象引用),可以通過一個IBinde發送
            Parcel data=Parcel.obtain();
            data.writeInt(helloService.getRandom());
            data.writeString("jack");
            Parcel reply=Parcel.obtain();
        	try {
				binder.transact(IBinder.LAST_CALL_TRANSACTION, data, reply, 0);
			} catch (RemoteException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
        	Log.i("ACTIVITY", "----Service回傳的值---->"+reply.readInt());
        	Log.i("ACTIVITY", "----Service回傳的值---->"+reply.readString());
			break;
		case R.id.button3:
			  //解除綁定
             unbindService(connection);
			break;
		}
	}

}