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() { @Override public void onClick(View v) { // TODO Auto-generated method stub Intent 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() { @Override public void onClick(View v) { // TODO Auto-generated method stub Intent 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() { @Override public 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 { @Override public 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 { @Override public void onReceive(Context context, Intent intent) { // TODO Auto-generated method stub Toast.makeText(context, "本次任务重复执行", Toast.LENGTH_SHORT).show(); } }

 

程序运行结果截图：