ANDROID_MARS学习笔记_S01原始版_019_SERVICE之Transact

一、代码
1.xml
(1)activity_main.xml

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     tools:context="com.transact.MainActivity" >

     <Button
         android:id="@+id/btn1"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="绑定" />
      <Button
         android:id="@+id/btn2"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="发送请求"
         android:layout_below="@id/btn1"/>

 </RelativeLayout>

(2)AndroidManifest.xml

 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.transact"
     android:versionCode="1"
     android:versionName="1.0" >

     <uses-sdk
         android:minSdkVersion="8"
         android:targetSdkVersion="21" />

     <application
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
         <activity
             android:name=".MainActivity"
             android:label="@string/app_name" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
         <service android:name=".ThirdService"></service>
     </application>

 </manifest>

2.java
(1)MainActivity.java

 package com.transact;

 import android.app.Activity;
 import android.content.ComponentName;
 import android.content.Intent;
 import android.content.ServiceConnection;
 import android.os.Binder;
 import android.os.Bundle;
 import android.os.IBinder;
 import android.os.Parcel;
 import android.os.RemoteException;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;

 public class MainActivity extends Activity {

     private Button btn1,btn2;
     private Binder binder;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         btn1 = (Button) findViewById(R.id.btn1);
         btn2 = (Button) findViewById(R.id.btn2);
         btn1.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View v) {
                 Intent intent = new Intent();
                 intent.setClass(MainActivity.this, ThirdService.class);
                 bindService(intent, conn, BIND_AUTO_CREATE);
             }
         });

         btn2.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View v) {
                 Parcel data = Parcel.obtain();
                 Parcel reply = Parcel.obtain();
                 data.writeString("data from activity");
                 try {
                     //Transact()会等待service的onTransact()方法往reply写数据，service的onTransact()执行完后会返回这里
                     binder.transact(0, data, reply, 0);
                     System.out.println("activity's replya data -->"+reply.readString());
                 } catch (RemoteException e) {
                     e.printStackTrace();
                 }
             }
         });
     }

     ServiceConnection conn = new ServiceConnection() {
         @Override
         public void onServiceDisconnected(ComponentName name) {

         }

         @Override
         public void onServiceConnected(ComponentName name, IBinder service) {
             MainActivity.this.binder = (Binder) service;
         }
     };
 }

(2)ThirdService.java

 package com.transact;

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

 public class ThirdService extends Service {

     @Override
     public IBinder onBind(Intent intent) {
         return new MyBinder();
     }

     class MyBinder extends Binder {
         @Override
         protected boolean onTransact(int code, Parcel data, Parcel reply,
                 int flags) throws RemoteException {
             System.out.println("code---->"+code);
             System.out.println("flags---->"+flags);
             System.out.println("data---->"+data.readString());
             reply.writeString("add data from thirdService");
             return super.onTransact(code, data, reply, flags);
         }
     }
 }