全局定时器 实现闹钟功能

http://book.51cto.com/art/201006/207068.htm

8.3.5 全局定时器AlarmManager（3）

本例使用BroadcastReceiver来处理定时提醒任务。BroadcastReceiver类的代码如下：

packagenet.blogjava.mobile;

importjava.util.Calendar;
importandroid.app.Activity;
importandroid.content.BroadcastReceiver;
importandroid.content.Context;
importandroid.content.Intent;
importandroid.content.SharedPreferences;
importandroid.media.MediaPlayer;

publicclassAlarmReceiverextendsBroadcastReceiver
{
@Override
publicvoidonReceive(Contextcontext,Intentintent)
{
 SharedPreferencessharedPreferences=context.getSharedPreferences(
"alarm_record",Activity.MODE_PRIVATE);
 Stringhour=String.valueOf(Calendar.getInstance().get(Calendar.HOUR_OF_DAY));
 Stringminute=String.valueOf(Calendar.getInstance().get(Calendar.MINUTE));
//从XML文件中获得描述当前时间点的value
 Stringtime=sharedPreferences.getString(hour+":"+minute,null);
if(time!=null)
{
//播放声音
 MediaPlayermediaPlayer=MediaPlayer.create(context,R.raw.ring);
mediaPlayer.start();
}
}
}

配置AlarmReceiver类的代码如下：

<receiverandroid:name=".AlarmReceiver"android:enabled="true"/>

在主程序中每添加一个时间点，就会在XML文件中保存所添加的时间点，代码如下：

packagenet.blogjava.mobile;

importandroid.app.Activity;
importandroid.app.AlarmManager;
importandroid.app.AlertDialog;
importandroid.app.PendingIntent;
importandroid.content.Context;
importandroid.content.DialogInterface;
importandroid.content.Intent;
importandroid.content.SharedPreferences;
importandroid.os.Bundle;
importandroid.view.View;
importandroid.view.View.OnClickListener;
importandroid.widget.Button;
importandroid.widget.TextView;
importandroid.widget.TimePicker;

publicclassMainextendsActivityimplementsOnClickListener
{
privateTextViewtvAlarmRecord;
privateSharedPreferencessharedPreferences;
@Override
publicvoidonClick(Viewv)
{
 Viewview=getLayoutInflater().inflate(R.layout.alarm,null);
 finalTimePickertimePicker=(TimePicker)view.findViewById(R.id.timepicker);
timePicker.setIs24HourView(true);
//显示设置时间点的对话框
newAlertDialog.Builder(this).setTitle("设置提醒时间").setView(view)
.setPositiveButton("确定",newDialogInterface.OnClickListener()
{
@Override
publicvoidonClick(DialogInterfacedialog,intwhich)
{
 StringtimeStr=String.valueOf(timePicker
.getCurrentHour())+":"
+String.valueOf(timePicker.getCurrentMinute());
//将时间点添加到TextView组件中
tvAlarmRecord.setText(tvAlarmRecord.getText().toString()+"\n"+timeStr);
//保存时间点
sharedPreferences.edit().putString(timeStr,timeStr).commit();
}
}).setNegativeButton("取消",null).show();
}
@Override
publicvoidonCreate(BundlesavedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
 ButtonbtnAddAlarm=(Button)findViewById(R.id.btnAddAlarm);
 tvAlarmRecord=(TextView)findViewById(R.id.tvAlarmRecord);
btnAddAlarm.setOnClickListener(this);
 sharedPreferences=getSharedPreferences("alarm_record",
Activity.MODE_PRIVATE);
 AlarmManageralarmManager=(AlarmManager)getSystemService(Context.ALARM_SERVICE);
 Intentintent=newIntent(this,AlarmReceiver.class);
//创建封装BroadcastReceiver的pendingIntent对象
 PendingIntentpendingIntent=PendingIntent.getBroadcast(this,0,intent,0);
//开始定时器，每1分钟执行一次
alarmManager.setRepeating(AlarmManager.RTC,0,60*1000,pendingIntent);
}
}

在使用本例添加若干个时间点后，会在alarm_record.xml文件中看到类似下面的内容：

<?xmlversion='1.0'encoding='utf-8'standalone='yes'?>
 <map>
 <stringname="18:52">18:52</string>
 <stringname="20:16">20:16</string>
 <stringname="19:11">19:11</string>
 <stringname="19:58">19:58</string>
 <stringname="22:51">22:51</string>
 <stringname="22:10">22:10</string>
 <stringname="22:11">22:11</string>
 <stringname="20:10">20:10</string>
 </map>

上面每个<string>元素都是一个时间点，定时器将每隔1分钟查一次alarm_record.xml文件。