AlarmManager的使用

在Android中有一个Alarm服务。假如要在未来的某个时间点执行一个任务或者重复执行某个任务。可以使用AlarmManager来实现。比如说闹钟。本节主要编写了一个AlarmManager的使用示例。

本节包含一个Activity和两个Receiver。

Activity如下：

package com.xiaochun91103;import java.util.Calendar;import android.app.Activity;import android.app.AlarmManager;import android.app.PendingIntent;import android.content.Intent;import android.os.Bundle;import android.os.SystemClock;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.Toast;public class AlarmController extends Activity { /** Called when the activity is first created. */private Button bt1,bt2,bt3;private Toast toast; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); bt1 = (Button)findViewById(R.id.bt1); bt2 = (Button)findViewById(R.id.bt2); bt3 = (Button)findViewById(R.id.bt3); bt1.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubIntent intent = new Intent(AlarmController.this,ExecuteOnce.class);PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this, 0, intent, 0);Calendar calendar = Calendar.getInstance();calendar.setTimeInMillis(System.currentTimeMillis());calendar.add(Calendar.SECOND, 10);AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);am.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), sender);if(toast != null) {toast.cancel();}toast = Toast.makeText(AlarmController.this, "10秒钟后执行一次Alarm", Toast.LENGTH_LONG);toast.show();} }); bt2.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubIntent intent = new Intent(AlarmController.this,RepeatingAlarm.class);long now = SystemClock.elapsedRealtime();PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this, 0, intent, 0);now = now+5*1000;AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, now, 5*1000, sender);if(toast != null) {toast.cancel();}toast = Toast.makeText(AlarmController.this, "每5秒重复执行", Toast.LENGTH_SHORT);toast.show();} }); bt3.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stub Intent intent = new Intent(AlarmController.this, RepeatingAlarm.class); PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this, 0, intent, 0); AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE); am.cancel(sender);if(toast != null) {toast.cancel();}toast = Toast.makeText(AlarmController.this, "结束Alarm", Toast.LENGTH_SHORT);toast.show();} }); }}

 

Receiver用来显示一个提示信息：

package com.xiaochun91103;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast;public class ExecuteOnce extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stub Toast.makeText(context, "本次任务执行一次", Toast.LENGTH_SHORT).show();}}

 

package com.xiaochun91103;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast;public class RepeatingAlarm extends BroadcastReceiver {@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stubToast.makeText(context, "本次任务重复执行", Toast.LENGTH_SHORT).show();}}

 

程序运行结果截图：