016_02startService与bindService的比较

　　使用startService()方法启动service，调用者与service之间没有关联，即使调用者退出了，服务仍然运行。

　　使用bindService()方法启动service，调用者与service绑定在一起，调用者一旦退出，服务也就终止。

　　Service使用了onBind 的方法去绑定服务，并返回一个Ibinder对象。具体的Service对象首先需要实现Binder对象，然后利用bindService的方法对Service进行绑定。当Ibinder对象返回具体的Service对象后，才可以获取service方法的内容。

com.example.day16_02servicedemo.MainActivity

    public void bindservice(View v){
        Intent  service = new Intent(this, MyService.class);
        conn =new MyServiceConnection();
        bindService(service, conn, Context.BIND_AUTO_CREATE);
    }

    class MyServiceConnection implements ServiceConnection{
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            binder =  (MyBinder) service;
            System.out.println("MainActivity.MyServiceConnection.onServiceConnected()");
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {        
            System.out.println("MainActivity.MyServiceConnection.onServiceDisconnected()");
        }    
    }

com.example.day16_02servicedemo.MyService

    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        System.out.println("MyService.onBind()");
        //当且仅当此处返回一个非空的Ibinder对象时，bindservice一端的Connection内的onserviceConnected函数才会被系统call到
        return new MyBinder();        
    }

    class MyBinder extends Binder{
        //内部类里面可以直接调用外部类的方法
        public String forworadgetruntimeinfo(){            
            return getruntimeinfo();
        }    
    }

1，当点击“启动服务”，Logcat输出：

2，退出该APP后，服务仍然存在；当重新回来点击“停止服务”，Logcat输出：

3，点击“绑定服务”，Logcat输出：

4，点击“解绑服务”或者退出App，Logcat输出：

相关源码如下：

package com.example.day16_02servicedemo;

import com.example.day16_02servicedemo.MyService.MyBinder;
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.view.View;

public class MainActivity extends Activity {
    MyServiceConnection conn;
    MyBinder binder;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void startservice(View v){
        Intent  service = new Intent(this, MyService.class);
        startService(service);    
    }
    
    public void stopservice(View v){    
        Intent  service = new Intent(this, MyService.class);
        stopService(service);
    }
     
    public void bindservice(View v){
        Intent  service = new Intent(this, MyService.class);
        conn =new MyServiceConnection();
        bindService(service, conn, Context.BIND_AUTO_CREATE);
    }
    
    public void unbindservice(View v){        
         unbindService(conn);
         conn =null;
    }
    
    
    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
         if (conn!=null) {
            unbindService(conn);
        }     
    }
    
    class MyServiceConnection implements ServiceConnection{
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            binder =  (MyBinder) service;
            System.out.println("MainActivity.MyServiceConnection.onServiceConnected()");
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {        
            System.out.println("MainActivity.MyServiceConnection.onServiceDisconnected()");
        }    
    }

    public void callservicefunc(View v){        
        //调用service内的方法
        //直接new service对象这种方式不行
        //需要从service给你传回来的这个内部类着手，解决问题        
       String info=    binder.forworadgetruntimeinfo();
       System.out.println("MainActivity.callservicefunc()"+info);     
    }
}

package com.example.day16_02servicedemo;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
 
public class MyService extends Service {
    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        System.out.println("MyService.onBind()");
        //当且仅当此处返回一个非空的Ibinder对象时，bindservice一端的Connection内的onserviceConnected函数才会被系统call到
        return new MyBinder();        
    }
        
    public String getruntimeinfo(){
        String info = "momory usage 5%";
        return info;
    }
    
    @Override
    public boolean onUnbind(Intent intent) {
        // TODO Auto-generated method stub
        System.out.println("MyService.onUnbind()");
        return super.onUnbind(intent);
    }

    @Override
    public void onRebind(Intent intent) {
        // TODO Auto-generated method stub
        super.onRebind(intent);
        System.out.println("MyService.onRebind()");
    }

    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        System.out.println("MyService.onCreate()");
    }
    
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // TODO Auto-generated method stub
        System.out.println("MyService.onStartCommand()");
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        System.out.println("MyService.onDestroy()");
    }

    class MyBinder extends Binder{
        //内部类里面可以直接调用外部类的方法
        public String forworadgetruntimeinfo(){            
            return getruntimeinfo();
        }    
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.day16_02servicedemo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        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=".MyService">
            <intent-filter>
                <action android:name="com.cskaoyan.service" />
         </intent-filter>           
        </service>
    </application>

</manifest>

<LinearLayout 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.example.day16_04remoteservicedemo.MainActivity" 
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="启动服务" 
        android:onClick="startservice"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="停止服务" 
        android:onClick="stopservice"/>     
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="绑定服务" 
        android:onClick="bindservice"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="解绑服务" 
        android:onClick="unbindservice"/>    
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="获取memory usage" 
        android:onClick="callservicefunc"/>
</LinearLayout>