Android - how to set an alarm to a specific date

问题:

I have seen a lot of tutorials and been trying for 2 hours now , though something is still wrong. I am very nervous now :) I want to set an alarm e.g. to 16:25 to go off, but nothing happens. I have this code:

   Calendar cur_cal = new GregorianCalendar();
    cur_cal.setTimeInMillis(System.currentTimeMillis());

    Calendar cal = new GregorianCalendar();
    cal.add(Calendar.DAY_OF_YEAR, cur_cal.get(Calendar.DAY_OF_YEAR));
    cal.set(Calendar.HOUR_OF_DAY, 16);
    cal.set(Calendar.MINUTE, 25);
    cal.set(Calendar.SECOND, 0);
    cal.set(Calendar.MILLISECOND, 0);

    alarmManager.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), pendingIntent);

I have also tried this:

 cal.set(Calendar.AM_PM, cur_cal.get(Calendar.AM_PM));
    cal.set(Calendar.HOUR, 4);

My final goal is to make it a repeating alarm, e.g. it should go off every day at the set time.

Update 01.17.2011. Still not working. I have this code:

           Calendar cal = Calendar.getInstance();
            cal.set(Calendar.YEAR, 2011);
            cal.set(Calendar.MONTH, Calendar.JANUARY); 
            cal.set(Calendar.DAY_OF_MONTH, 17);
            cal.set(Calendar.HOUR_OF_DAY, 16);
            cal.set(Calendar.MINUTE, 58);
         cal.set(Calendar.SECOND, 0);
          cal.set(Calendar.MILLISECOND, 0);

I have also tried this:

 cal.set(Calendar.HOUR, 4);
 cal.set(Calendar.AM_PM, Calendar.PM);

and this:

cal.set(Calendar.HOUR_OF_DAY, 4 );
            cal.set(Calendar.AM_PM, Calendar.PM);

回答1:

package your.pack.name;

import java.util.Calendar;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;

public class AlarmActivity extends Activity {
    /** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Calendar cal = Calendar.getInstance();

        cal.setTimeInMillis(System.currentTimeMillis());
        cal.clear();
        cal.set(2012,2,8,18,16);

        AlarmManager alarmMgr = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(this, AlarmReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
       // cal.add(Calendar.SECOND, 5);
        alarmMgr.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), pendingIntent);


    }
}

回答2:

Usually you shouldn't obtain Calendar like you do, there is Calendar.getInstance() method for that:

Calendar cal = Calendar.getInstance();

That gives you a calendar with all fields set to current date, then just:

cal.set(Calendar.HOUR_OF_DAY, 16);
cal.set(Calendar.MINUTE, 25);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);

alarmManager.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), pendingIntent);

回答3:

The following code works perfectly for alarm. The date and time i mentioned here is : 2012- June- 28, 11:20:00 AM. And the most important thing is, month is specified from 0 t0 11 only. Means June should be specified by 5.

        AlarmManager objAlarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);              
        Calendar objCalendar = Calendar.getInstance();
        objCalendar.set(Calendar.YEAR, 2012);
        //objCalendar.set(Calendar.YEAR, objCalendar.get(Calendar.YEAR));
        objCalendar.set(Calendar.MONTH, 5);
        objCalendar.set(Calendar.DAY_OF_MONTH, 28);
        objCalendar.set(Calendar.HOUR_OF_DAY, 11);
        objCalendar.set(Calendar.MINUTE, 20);
        objCalendar.set(Calendar.SECOND, 0);
        objCalendar.set(Calendar.MILLISECOND, 0);
        objCalendar.set(Calendar.AM_PM, Calendar.AM);         

        Intent alamShowIntent = new Intent(this,AlarmActivity.class);
        PendingIntent alarmPendingIntent = PendingIntent.getActivity(this, 0,alamShowIntent,0 );

        objAlarmManager.set(AlarmManager.RTC_WAKEUP,objCalendar.getTimeInMillis(), alarmPendingIntent);

回答4:

You are not setting the year in your Calendar object.

Also, note that new GregorianCalendar() already sets the value to the current date and time.