代码贴上：

1.MainActivity.java:

package com.test.Alarm;

import com.test.Alarm.R;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.SystemClock;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {
private Button msetButton;
private Button mcancelButton;
private TextView mTextView;
private final int REQUEST_CODE_0 = 0;
private final int REQUEST_CODE_1 = 1;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextView = (TextView) this.findViewById(R.id.mText);
msetButton = (Button) this.findViewById(R.id.setTimeButton);
mcancelButton = (Button) findViewById(R.id.cancelButton);

msetButton.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
AlarmManager alarmMgr = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(getApplicationContext(),
AlermReceiver.class);
intent.putExtra("flag", true);
// 创建2个PendingIntent
PendingIntent setPendIntent0 = PendingIntent.getBroadcast(
getApplicationContext(), REQUEST_CODE_0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
Log.e("FLAG_UPDATE_CURRENT-->setPendIntent0：", setPendIntent0
+ "");

PendingIntent setPendIntent1 = PendingIntent.getBroadcast(
getApplicationContext(), REQUEST_CODE_1, intent,
PendingIntent.FLAG_UPDATE_CURRENT);
Log.e("FLAG_UPDATE_CURRENT-->setPendIntent1：", setPendIntent1
+ "");

// 5秒后发送广播，然后每隔10秒重复发广播
int triggerAtTime = (int) (SystemClock.elapsedRealtime() + 5 * 1000);
int interval = 10 * 1000;

// 注册以上创建的2个PendingIntent，每隔10秒重复发广播
alarmMgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
triggerAtTime, interval, setPendIntent0);
alarmMgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
triggerAtTime, interval, setPendIntent1);

// alarmMgr.set(AlarmManager.ELAPSED_REALTIME_WAKEUP,
// triggerAtTime, pendIntent1);

}
});
mcancelButton.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {

AlarmManager alarmMgr = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(getApplicationContext(),
AlermReceiver.class);
intent.putExtra("flag", false);
PendingIntent StopPendIntent0 = PendingIntent.getBroadcast(
getApplicationContext(), REQUEST_CODE_0, intent,
PendingIntent.FLAG_UPDATE_CURRENT);

/**
* 如果你想更新putExtra中flag的值为false，那么你必须通过alarmMgr的setxxx()方法再注册一次，
* 相当于更新已经存在的intent，如果不这样做，你就无法达到更新的目的，像这样：
*
* alarmMgr.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, 0,
* StopPendIntent0);
*
* 然后你再执行alarmMgr.cancel(StopPendIntent0);取消掉
*
* 这个可能就是你通过flag这个标志启动了一个闹钟，并响铃了，又想通过flag来关闭闹钟却咋都不能关闭的原因，
* 问题可能就在这里， 因为实际上你没有更新数据
*/
// alarmMgr.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, 0,
// StopPendIntent0);