Set Alarms to Specific Date and Time in Android

Question

Hi friends, Please kindly have a look at this. I am trying to set an alarm for a specific time and date. It does not seem to be working and i don't really know why.

             Calendar cal = Calendar.getInstance();

         cal.setTimeInMillis(System.currentTimeMillis());
         cal.set(Calendar.YEAR, mYear);
         cal.set(Calendar.MONTH,mMonth);
         cal.set(Calendar.DAY_OF_MONTH,mDay);
         cal.set(Calendar.HOUR,mHour);
         cal.set(Calendar.MINUTE,mMinutes);

// where mYear, mMonths, mDay, mHour and mMinutes are int values from the Date and Time picker dialogs respectively

     Intent activate = new Intent(this, Alarm.class);
     PendingIntent alarmIntent = PendingIntent.getBroadcast(this, 0, activate, 0);
     alarms = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
     alarms.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), alarmIntent);

just to let you know, it works if i replace the cal.getTimeInMillis() with System.CurrentTimeInMillis() in the alarms.set() methods. But thats obviously what i don't want. Thanks

Answer 1

Try this Manuel, Hope this one works for u

package com.example.android.apis.app;

// Need the following import to get access to the app resources, since this
// class is in a sub-package.
import com.example.android.apis.R;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.SystemClock;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

import java.util.Calendar;

/**
 * Example of scheduling one-shot and repeating alarms.  See
 * {@link OneShotAlarm} for the code run when the one-shot alarm goes off, and
 * {@link RepeatingAlarm} for the code run when the repeating alarm goes off.
 * <h4>Demo</h4>
App/Service/Alarm Controller

<h4>Source files</h4>
<table class="LinkTable">
        <tr>
            <td class="LinkColumn">src/com.example.android.apis/app/AlarmController.java</td>
            <td class="DescrColumn">The activity that lets you schedule alarms</td>
        </tr>
        <tr>
            <td class="LinkColumn">src/com.example.android.apis/app/OneShotAlarm.java</td>
            <td class="DescrColumn">This is an intent receiver that executes when the
                one-shot alarm goes off</td>
        </tr>
        <tr>
            <td class="LinkColumn">src/com.example.android.apis/app/RepeatingAlarm.java</td>
            <td class="DescrColumn">This is an intent receiver that executes when the
                repeating alarm goes off</td>
        </tr>
        <tr>
            <td class="LinkColumn">/res/any/layout/alarm_controller.xml</td>
            <td class="DescrColumn">Defines contents of the screen</td>
        </tr>
</table>

 */
public class AlarmController extends Activity {
    Toast mToast;

    @Override
        protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.alarm_controller);

        // Watch for button clicks.
        Button button = (Button)findViewById(R.id.one_shot);
        button.setOnClickListener(mOneShotListener);
        button = (Button)findViewById(R.id.start_repeating);
        button.setOnClickListener(mStartRepeatingListener);
        button = (Button)findViewById(R.id.stop_repeating);
        button.setOnClickListener(mStopRepeatingListener);
    }

    private OnClickListener mOneShotListener = new OnClickListener() {
        public void onClick(View v) {
            // When the alarm goes off, we want to broadcast an Intent to our
            // BroadcastReceiver.  Here we make an Intent with an explicit class
            // name to have our own receiver (which has been published in
            // AndroidManifest.xml) instantiated and called, and then create an
            // IntentSender to have the intent executed as a broadcast.
            Intent intent = new Intent(AlarmController.this, OneShotAlarm.class);
            PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this,
                    0, intent, 0);

            // We want the alarm to go off 30 seconds from now.
            Calendar calendar = Calendar.getInstance();
            calendar.setTimeInMillis(System.currentTimeMillis());
            calendar.add(Calendar.SECOND, 30);

            // Schedule the alarm!
            AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
            am.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), sender);

            // Tell the user about what we did.
            if (mToast != null) {
                mToast.cancel();
            }
            mToast = Toast.makeText(AlarmController.this, R.string.one_shot_scheduled,
                    Toast.LENGTH_LONG);
            mToast.show();
        }
    };

    private OnClickListener mStartRepeatingListener = new OnClickListener() {
        public void onClick(View v) {
            // When the alarm goes off, we want to broadcast an Intent to our
            // BroadcastReceiver.  Here we make an Intent with an explicit class
            // name to have our own receiver (which has been published in
            // AndroidManifest.xml) instantiated and called, and then create an
            // IntentSender to have the intent executed as a broadcast.
            // Note that unlike above, this IntentSender is configured to
            // allow itself to be sent multiple times.
            Intent intent = new Intent(AlarmController.this, RepeatingAlarm.class);
            PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this,
                    0, intent, 0);

            // We want the alarm to go off 30 seconds from now.
            long firstTime = SystemClock.elapsedRealtime();
            firstTime += 15*1000;

            // Schedule the alarm!
            AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
            am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
                            firstTime, 15*1000, sender);

            // Tell the user about what we did.
            if (mToast != null) {
                mToast.cancel();
            }
            mToast = Toast.makeText(AlarmController.this, R.string.repeating_scheduled,
                    Toast.LENGTH_LONG);
            mToast.show();
        }
    };

    private OnClickListener mStopRepeatingListener = new OnClickListener() {
        public void onClick(View v) {
            // Create the same intent, and thus a matching IntentSender, for
            // the one that was scheduled.
            Intent intent = new Intent(AlarmController.this, RepeatingAlarm.class);
            PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this,
                    0, intent, 0);

            // And cancel the alarm.
            AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
            am.cancel(sender);

            // Tell the user about what we did.
            if (mToast != null) {
                mToast.cancel();
            }
            mToast = Toast.makeText(AlarmController.this, R.string.repeating_unscheduled,
                    Toast.LENGTH_LONG);
            mToast.show();
        }
    };
}

Answer 2

Idiot me!! found the solution. All i had to do first, was call the clear method of the Calendar object after getting an instance.

Calendar cal = Calendar.getInstance();
cal.setTimeInMillis(System.currentTimeMillis());
cal.clear();