Android笔记二十九.Service组件入门(三).使用IntentService

package com.example.android_intentservice;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class ServiceAndIntentService extends Activity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
 }
 //1.启动普通Service按钮方法
 public void startService(View source)
 {
  Intent intent = new Intent(this,MyService.class);	//创建需要启动的service的Intent
  startService(intent);	 //启动Intent指定的Service
 }
 //2.启动IntentService按钮方法
 public void startIntentService(View source)
 {
  Intent intent = new Intent(this,MyIntentService.class);
  startService(intent);
 }
}

  ......
  <Button
      android:onClick="startService"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="启动普通Service" />
  <Button
          android:onClick="startIntentService"
          android:layout_width="186dp"
          android:layout_height="wrap_content"
          android:text="启动IntentService" />

package com.example.android_intentservice;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
public class MyService extends Service {
 @Override
 public IBinder onBind(Intent intent) {
  return null;
 }
 //当启动Service，调用该方法执行相应代码
 @Override
 public int onStartCommand(Intent intent, int flags, int startId) {
  long endTime = System.currentTimeMillis()+20*1000;
  System.out.println("onStart");
  while(System.currentTimeMillis()<endTime)
  {
   synchronized(this)
   {
    try
    {
     wait(endTime-System.currentTimeMillis());
    }catch(Exception e)
    {
    }
   }
  }
  System.out.println("---普通Service耗时任务执行完成---");
  return START_STICKY;
 }
 
}
(4)\src\com\example\android_intentservice\MyIntentService.java
实现：实现一个IntentService执行耗时任务(20s)，观察是否导致ANR异常
package com.example.android_intentservice;
import android.app.IntentService;
import android.content.Intent;
public class MyIntentService extends IntentService {
 public MyIntentService() {
  super("MyIntentService");
 }
 //IntentService会使用单独的线程来执行方法的代码
 @Override
 protected void onHandleIntent(Intent intent) {
  //该方法内可以执行任何耗时任务，比如下载文件等，此处只是让线程暂停20s
  long endTime = System.currentTimeMillis()+20*1000;
  System.out.println("onStart");
  while(System.currentTimeMillis()<endTime)
  {
   synchronized(this)
   {
    try
    {
     wait(endTime-System.currentTimeMillis());
    }catch(Exception e)
    {
    }
   }
  }
  System.out.println("---IntentService耗时任务执行完成---");
 }
}

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
          ..........
        </activity>
        <!--配置service-->
        <service android:name=".MyService"/>
        <service android:name=".MyIntentService"/>
    </application>