新建一个Service来模拟后台执行的程序，PollingService.java:
package com.ryantang.rtpollingdemo;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
/**
* Polling service
* @Author Ryan
* @Create 2013-7-13 涓婂崍10:18:44
*/
public class PollingService extends Service {
public static final String ACTION = "com.ryantang.service.PollingService";
private Notification mNotification;
private NotificationManager mManager;
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate() {
initNotifiManager();
}
@Override
public void onStart(Intent intent, int startId) {
new PollingThread().start();
}
//初始化通知栏配置
private void initNotifiManager() {
mManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
int icon = R.drawable.ic_launcher;
mNotification = new Notification();
mNotification.icon = icon;
mNotification.tickerText = "New Message";
mNotification.defaults |= Notification.DEFAULT_SOUND;
mNotification.flags = Notification.FLAG_AUTO_CANCEL;
}
//弹出Notification
private void showNotification() {
mNotification.when = System.currentTimeMillis();
//Navigator to the new activity when click the notification title
Intent i = new Intent(this, MessageActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, i,
Intent.FLAG_ACTIVITY_NEW_TASK);
mNotification.setLatestEventInfo(this,
getResources().getString(R.string.app_name), "You have new message!", pendingIntent);
mManager.notify(0, mNotification);
}
/**
* Polling thread
* 模拟向Server轮询的异步线程
* @Author Ryan
* @Create 2013-7-13 涓婂崍10:18:34
*/
int count = 0;
class PollingThread extends Thread {
@Override
public void run() {
System.out.println("Polling...");
count ++;
//当计数能被5整除时弹出通知
if (count % 5 == 0) {
showNotification();
System.out.println("New message!");
}
}
}
@Override
public void onDestroy() {
super.onDestroy();
System.out.println("Service:onDestroy");
}
}
别望了在AndroidManifest.xml中注册Service：
<service android:name="com.ryantang.rtpollingdemo.PollingService">
<intent-filter>
<action android:name="com.ryantang.service.PollingService"/>
</intent-filter>
</service>
当计数能被5整除时弹出通知，点击通知后进入MessageActivity.java:
package com.ryantang.rtpollingdemo;
import android.app.Activity;
import android.app.NotificationManager;
import android.content.Context;
import android.os.Bundle;
public class MessageActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_message);
System.out.println("新的activity");
NotificationManager manager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
manager.cancelAll();
}
}
使用AlarmManager封装已给PollingUtils.java来执行Service的启动和停止，PollingUtils.java:
package com.ryantang.rtpollingdemo;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.SystemClock;
/**
* Polling Tools
* @Author Ryan
* @Create 2013-7-13 涓婂崍10:14:43
*/
public class PollingUtils {
/**开启轮询服务
* @param context
* @param seconds 定期执行的时间间隔
* @param cls
* @param action
*/
public static void startPollingService(Context context, int seconds, Class<?> cls,String action) {
//获取AlarmManager系统服务
AlarmManager manager = (AlarmManager) context
.getSystemService(Context.ALARM_SERVICE);
//包装需要执行Service的Intent
Intent intent = new Intent(context, cls);
intent.setAction(action);
PendingIntent pendingIntent = PendingIntent.getService(context, 0,
intent, PendingIntent.FLAG_UPDATE_CURRENT);
//触发服务的起始时间
long triggerAtTime = SystemClock.elapsedRealtime();
//使用AlarmManager的setRepeating方法设置定期执行时间间隔（seconds秒）和需要执行的Service
manager.setRepeating(AlarmManager.ELAPSED_REALTIME, triggerAtTime,
seconds * 1000, pendingIntent);
}
/**
* 停止轮询服务
* @param context
* @param cls
* @param action
*/
public static void stopPollingService(Context context, Class<?> cls,String action) {
//获取AlarmManager系统服务
AlarmManager manager = (AlarmManager) context
.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, cls);
intent.setAction(action);
PendingIntent pendingIntent = PendingIntent.getService(context, 0,
intent, PendingIntent.FLAG_UPDATE_CURRENT);
//取消正在执行的服务
manager.cancel(pendingIntent);
}
}
最后在主程序中执行，MainActivity.java:
package com.ryantang.rtpollingdemo;
import android.app.Activity;
import android.os.Bundle;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Start polling service
System.out.println("Start polling service...");
PollingUtils.startPollingService(this, 30, PollingService.class,
PollingService.ACTION);// PollingService.ACTION与AndroidManifest.xml一一对应
}
@Override
protected void onDestroy() {
super.onDestroy();
// Stop polling service
System.out.println("Stop polling service...");
PollingUtils.stopPollingService(this, PollingService.class,
PollingService.ACTION);
}
}
Android之AlarmManager(全局定时器/闹钟）指定时长或以周期形式执行某项操作
（1）在指定时长后执行某项操作
//操作：发送一个广播，广播接收后Toast提示定时操作完成
Intent intent =new Intent(Main.this, alarmreceiver.class);
intent.setAction("short");
PendingIntent sender=
PendingIntent.getBroadcast(Main.this, 0, intent, 0);
//设定一个五秒后的时间
Calendar calendar=Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.add(Calendar.SECOND, 5);
AlarmManager alarm=(AlarmManager)getSystemService(ALARM_SERVICE);
alarm.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), sender);
//或者以下面方式简化
//alarm.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+5*1000, sender);
//注意：receiver记得在manifest.xml注册，使用的是静态的广播消息机制
public static class alarmreceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
if(intent.getAction().equals("short")){
Toast.makeText(context, "short alarm", Toast.LENGTH_LONG).show();
}else{
Toast.makeText(context, "repeating alarm",Toast.LENGTH_LONG).show();
}
}
}
<receiver android:name="" >
<intent-filter >
<action android:name="short"><action />
</intent-filter>
</receiver>
AlarmManager类型如下：
AlarmManager.RTC，硬件闹钟，不唤醒手机（也可能是其它设备）休眠；当手机休眠时不发射闹钟。
AlarmManager.RTC_WAKEUP，硬件闹钟，当闹钟发射时唤醒手机休眠；
AlarmManager.ELAPSED_REALTIME，真实时间流逝闹钟，不唤醒手机休眠；在指定的延时过后，发送广播，但不唤醒设备。
AlarmManager.ELAPSED_REALTIME_WAKEUP，真实时间流逝闹钟，当闹钟发射时唤醒手机休眠；
RTC闹钟和ELAPSED_REALTIME最大的差别就是前者可以通过修改手机时间触发闹钟事件，后者要通过真实时间的流逝，即使在休眠状态，时间也会被计算。
（2）周期性的执行某项操作
Intent intent =new Intent(Main.this, alarmreceiver.class);
intent.setAction("repeating");
PendingIntent sender=PendingIntent
.getBroadcast(Main.this, 0, intent, 0);
//开始时间
long firstime=SystemClock.elapsedRealtime();
AlarmManager am=(AlarmManager)getSystemService(ALARM_SERVICE);
//5秒一个周期，不停的发送广播
am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, firstime, 5*1000, sender);
AlarmManager的setRepeating()相当于Timer的Schedule(task,delay,peroid);有点差异的地方时Timer这个方法是指定延迟多长时间以后开始周期性的执行task;
AlarmManager的取消：（其中需要注意的是取消的Intent必须与启动Intent保持绝对一致才能支持取消AlarmManager）
Intent intent =new Intent(Main.this, alarmreceiver.class);
intent.setAction("repeating");
PendingIntent sender=PendingIntent
.getBroadcast(Main.this, 0, intent, 0);
AlarmManager alarm=(AlarmManager)getSystemService(ALARM_SERVICE);
alarm.cancel(sender);
时间： 2024-10-12 23:21:44