这个应用实现了简单的闹钟功能，关闭程序的状态中也可以进行闹钟的提醒。
这里遗留了一个问题：
如果我通过应用本身关闭程序，是可以实现我上述所说的功能，但是如果我在手机进程管理中实现应用程序的关闭操作，这个提醒就不起作用了，我很疑惑的是，我通过应用程序本身关闭了后，在进程中也是查看不到这个应用了的。所以哪位知道的帮留个言指点下，谢谢。
ClockDemo.java

package com.example.clock;

import java.util.Calendar;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.TimePickerDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.Button;
import android.widget.TimePicker;

public class ClockDemo extends Activity {

 private Button mSet;
 Calendar mCalendar = Calendar.getInstance();

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main);
 ObjectPool.mAlarmHelper = new AlarmHelper(this);
 mSet = (Button) findViewById(R.id.mSet);
 setListener();
 }

 public void setListener() {
 mSet.setOnClickListener(new View.OnClickListener() {
  public void onClick(View v) {
  mCalendar.setTimeInMillis(System.currentTimeMillis());
  int mHour = mCalendar.get(Calendar.HOUR_OF_DAY);
  int mMinute = mCalendar.get(Calendar.MINUTE);
  new TimePickerDialog(ClockDemo.this,
   new TimePickerDialog.OnTimeSetListener() {
    public void onTimeSet(TimePicker view,
     int hourOfDay, int minute) {
    mCalendar.setTimeInMillis(System
     .currentTimeMillis());
    mCalendar.set(Calendar.HOUR_OF_DAY, hourOfDay);
    mCalendar.set(Calendar.MINUTE, minute);
    mCalendar.set(Calendar.SECOND, 0);
    mCalendar.set(Calendar.MILLISECOND, 0);
    ObjectPool.mAlarmHelper.openAlarm(32, "ddd",
     "ffff", mCalendar.getTimeInMillis());
    }
   }, mHour, mMinute, true).show();
  }
 });
 }

 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
 if (keyCode == KeyEvent.KEYCODE_BACK) {
  showBackDialog();
  return true;
 }
 return super.onKeyDown(keyCode, event);
 }

 /** Give the tip when exit the application. */
 public void showBackDialog() {
 final AlertDialog.Builder builder = new AlertDialog.Builder(this);
 builder.setTitle("提示")
  .setIcon(R.drawable.icon)
  .setMessage("是否退出?")
  .setPositiveButton("sure",
   new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog,
     int which) {
    System.exit(0);
    android.os.Process
     .killProcess(android.os.Process.myPid());

    dialog.dismiss();
    }
   })
  .setNegativeButton("cancel",
   new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog,
     int which) {
    dialog.dismiss();
    }
   });
 AlertDialog ad = builder.create();
 ad.show();
 }

}

AlarmHelper.java

package com.example.clock;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;

public class AlarmHelper {

 private Context c;
 private AlarmManager mAlarmManager;

 public AlarmHelper(Context c) {
 this.c = c;
 mAlarmManager = (AlarmManager) c
  .getSystemService(Context.ALARM_SERVICE);
 }

 public void openAlarm(int id, String title, String content, long time) {
 Intent intent = new Intent();
 intent.putExtra("_id", id);
 intent.putExtra("title", title);
 intent.putExtra("content", content);
 intent.setClass(c, CallAlarm.class);
 PendingIntent pi = PendingIntent.getBroadcast(c, id, intent,
  PendingIntent.FLAG_UPDATE_CURRENT);
 mAlarmManager.set(AlarmManager.RTC_WAKEUP, time, pi);
 }

 public void closeAlarm(int id, String title, String content) {
 Intent intent = new Intent();
 intent.putExtra("_id", id);
 intent.putExtra("title", title);
 intent.putExtra("content", content);
 intent.setClass(c, CallAlarm.class);
 PendingIntent pi = PendingIntent.getBroadcast(c, id, intent, 0);
 mAlarmManager.cancel(pi);
 }
}

CallAlarm.java

package com.example.clock;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class CallAlarm extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
 intent.setClass(context, AlarmAlert.class);
 intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 context.startActivity(intent);
 }
}

AlarmAlert.java

package com.example.clock;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;

public class AlarmAlert extends Activity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 new AlertDialog.Builder(AlarmAlert.this)
  .setIcon(R.drawable.clock)
  .setTitle("ddd")
  .setMessage("fff")
  .setPositiveButton("ddd",
   new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog,
     int whichButton) {
    System.exit(0);
    android.os.Process
     .killProcess(android.os.Process.myPid());
    }
   }).show();
 }
}
ObjectPool.java
public class ObjectPool {

 /** The alarm object. */
 public static AlarmHelper mAlarmHelper;

}

看了那么多，估计某些人又嫌烦了，我只贴上代码的目的是希望大家能看代码，而不是电脑上下了一个又一个的源文件，只知道用而不关心其中的技术点，这样就不能举一番三了。

源码下载：http://xiazai.jb51.net/201607/yuanma/ClockDemo(jb51.net).rar

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。