Service + Handler + Thread

Service通知Activity修改UI（UI動態更新）有兩種方式：
1. 通過service發送廣播通知activity修改UI的内容；
2. 通过Handler進行傳值更新

ref: 千寻

MainActivity.java

package com.example.handler_service;

import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;

public class MainActivity extends ActionBarActivity
{
 private Intent testService;
 public static Handler mHandler;
 private ImageView ui_imgLoginImg = null;
 
 @Override
 protected void onCreate(Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  mHandler = new Handler() 
  {
   public void handleMessage(Message msg)
   {
    super.handleMessage(msg);
    initUI();
    parseMsg(msg);
   }
  };
  
  testService = new Intent(this, testService.class);
  startService(testService);
  
 }
 
 private void initUI()
 {
  ui_imgLoginImg = (ImageView) findViewById(R.id.idImagePhotoID);
 }
 
 private void parseMsg(Message msg)
 {
  switch (msg.what)
  {
   case 0: //貼圖
    int id = getResources().getIdentifier("com.example.robotserver:drawable/" + "testpng" , null, null);
    ui_imgLoginImg.setImageResource(id);
    break;
   case 1: //取消貼圖
    ui_imgLoginImg.invalidate();
    ui_imgLoginImg.setImageResource(0);
    break;
  }
 }
 
}

testService.java

package com.example.handler_service;

import android.app.Service;
import android.content.Intent;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Message;

public class testService extends Service
{
 @Override
    public void onCreate()
    {
     super.onCreate();
     testThread.start();
    }
 @Override
 public IBinder onBind(Intent intent)
 {
  return null;
 }
 Thread testThread = new Thread() 
 {
  Bundle countBundle = new Bundle();
  @Override
  public void run()
  {
   super.run();
   
   Message msg = new Message();
   msg.what=0;
   msg.setData(countBundle);
   MainActivity.mHandler.sendMessage(msg);
  }
 };
}

使用Service時記得在 AndroidManifest.xml 加上： (路徑不可錯)

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <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 -->
        <service android:name="com.example.handler_service.testService" >
        </service>
    </application>

</manifest>