package cc.testservice3;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
* Demo描述:
* IntentService的使用
*
* Demo详情:
* 在此处使用Service和IntentService模拟耗时任务.
* 那么Service会出现ANR错误,IntentService则不会
*
* 原因说明:
* 1 Service不是专门启动的一条单独进程,Service与它所在的应用位于同一进程中
* 2 Service也不是一条新的线程,所以不能在Service里面处理耗时的任务
*
* IntentService继承自Service但是会在onHandleIntent()中开启新的线程
* 来处理任务,所以不会造成ANR
*/
public class MainActivity extends Activity {
private Button mStartServiceButton;
private Button mStartIntentServiceButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
}
private void init(){
//利用Service操作耗时任务
mStartServiceButton=(Button) findViewById(R.id.startServiceButton);
mStartServiceButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent intent=new Intent(MainActivity.this, ServiceSubclass.class);
startService(intent);
}
});
//利用IntentService操作耗时任务
mStartIntentServiceButton=(Button) findViewById(R.id.startIntentServiceButton);
mStartIntentServiceButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent intent=new Intent(MainActivity.this, IntentServiceSubclass.class);
startService(intent);
}
});
}
}
package cc.testservice3;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
public class ServiceSubclass extends Service {
@Override
public IBinder onBind(Intent arg0) {
return null;
}
public void onCreate() {
System.out.println("---> Service onCreate()");
}
@Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
System.out.println("---> Service onStart()");
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
System.out.println("---> Service onStartCommand()");
//模拟耗时的操作
try {
Thread.sleep(30*1000);
} catch (Exception e) {
e.printStackTrace();
}
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy() {
super.onDestroy();
System.out.println("---> Service onDestroy()");
}
}
package cc.testservice3;
import android.app.IntentService;
import android.content.Intent;
/**
* 注意事项:
* 在继承自IntentService时Eclipse会提示生成一个带String参数的
* 构造方法.我们按照该提示生成构造方法后,运行时会报错:
* java.lang.InstantiationException
*
* 解决办法:
* 删除该提示生成的构造方法,写一个空参数的构造方法.
* 但在该空参数构造方法里执行super("");
*
*/
public class IntentServiceSubclass extends IntentService {
public IntentServiceSubclass() {
super("");
}
@Override
protected void onHandleIntent(Intent intent) {
//模拟耗时的操作
try {
Thread.sleep(30*1000);
} catch (Exception e) {
e.printStackTrace();
}
}
}
<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:orientation="vertical"
android:gravity="center_horizontal"
>
<Button
android:id="@+id/startServiceButton"
android:layout_width="200dip"
android:layout_height="150dip"
android:text="启动Service"
/>
<Button
android:id="@+id/startIntentServiceButton"
android:layout_width="200dip"
android:layout_height="150dip"
android:text="启动IntentService"
/>
</LinearLayout>
