Create a alarm manager to trigger at 9.30 PM everyday and display a notification to the user

Hello Everyone, In the code, I just simply trigger an alarm at 9.30 PM every day and show a notification to the user. You can modify the code according to you need For more detailed information you can visit official android website https://developer.android.com/training/scheduling/alarms

	class MainActivity : Activity() {
	override fun onCreate(savedInstanceState: Bundle?) {
	super.onCreate(savedInstanceState)
	setContentView(R.layout.activity_main)
	//set alarm time to 9:30 PM to trigger
	val calendar: Calendar = Calendar.getInstance()
	calendar.set(Calendar.HOUR_OF_DAY, 21)
	calendar.set(Calendar.MINUTE, 30)
	calendar.set(Calendar.SECOND, 0)
	val al = com.app.base.ReminderServices.AlarmReceiver()
	al.setAlarm(this@MainActivity, calendar, Random().nextInt(10) + 1)
	}

view raw AlarmActivity.kt hosted with ❤ by GitHub

	package com.app.base.ReminderServices
	import android.content.BroadcastReceiver
	import android.content.Context
	import android.content.Intent
	import java.util.*
	/**
	* Created by Suraj Bahadur on 17-Aug-20.
	*/
	class AlarmBootReceiver : BroadcastReceiver() {
	override fun onReceive(ctx: Context?, intent: Intent?) {
	try {
	if (intent!!.action == "android.intent.action.BOOT_COMPLETED") {
	// Set the alarm here.
	val calendar: Calendar = Calendar.getInstance()
	calendar.set(Calendar.HOUR_OF_DAY, 21)
	calendar.set(Calendar.MINUTE, 30)
	calendar.set(Calendar.SECOND, 0)
	val al = AlarmReceiver()
	al.setAlarm(ctx!!, calendar, Random().nextInt(10) + 1)
	}
	} catch (e: Exception) {
	e.printStackTrace()
	}
	}
	}

view raw AlarmBootReceiver.kt hosted with ❤ by GitHub

	package com.app.base.ReminderServices
	import android.app.AlarmManager
	import android.app.NotificationChannel
	import android.app.NotificationManager
	import android.app.PendingIntent
	import android.content.ComponentName
	import android.content.Context
	import android.content.Intent
	import android.content.pm.PackageManager
	import android.graphics.BitmapFactory
	import android.graphics.Color
	import android.os.Build
	import android.provider.Settings
	import androidx.core.app.NotificationCompat
	import androidx.core.content.ContextCompat
	import androidx.legacy.content.WakefulBroadcastReceiver
	import com.app.base.R
	import com.app.base.activity.MainActivity
	import java.util.*
	class AlarmReceiver : WakefulBroadcastReceiver() {
	var mAlarmManager: AlarmManager? = null
	var mPendingIntent: PendingIntent? = null
	override fun onReceive(context: Context, intent: Intent) {
	val mNotificationManager = context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
	if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
	val channel = NotificationChannel("default", CHANNEL_NAME, NotificationManager.IMPORTANCE_HIGH)
	channel.description = "温馨提示：請把回收桶掛於門外，以便明天上午九時至下午六時回收。若回收時段內沒有把回收桶掛於門外，本星期將不會回收"
	channel.lightColor = Color.parseColor("#067EE8")
	mNotificationManager.createNotificationChannel(channel)
	}
	val mBuilder = NotificationCompat.Builder(context, "default")
	.setSmallIcon(R.mipmap.ic_launcher) // notification icon
	.setLargeIcon(BitmapFactory.decodeResource(context.resources, R.drawable.dustbin))
	.setContentTitle("回收通知") // title for notification
	.setContentText("温馨提示：請把回收桶掛於門外，以便明天上午九時至下午六時回收。若回收時段內沒有把回收桶掛於門外，本星期將不會回收") // message for notification
	.setSound(Settings.System.DEFAULT_NOTIFICATION_URI) // set alarm sound for notification
	.setChannelId("default")
	.setColor(ContextCompat.getColor(context, R.color.colorPrimary))
	.setAutoCancel(true) // clear notification after click
	val intent1 = Intent(context, MainActivity::class.java)
	val pi = PendingIntent.getActivity(context, 0, intent1, PendingIntent.FLAG_ONE_SHOT)
	mBuilder.setContentIntent(pi)
	mNotificationManager.notify(0, mBuilder.build())
	}
	fun setAlarm(context: Context, calendar: Calendar, ID: Int) {
	mAlarmManager = context.getSystemService(Context.ALARM_SERVICE) as AlarmManager
	// Put Reminder ID in Intent Extra
	val intent = Intent(context, AlarmReceiver::class.java)
	intent.putExtra("TaskID_Alarm", Integer.toString(ID))
	mPendingIntent = PendingIntent.getBroadcast(context, ID, intent, PendingIntent.FLAG_CANCEL_CURRENT)
	// Calculate notification time
	val c = Calendar.getInstance()
	mAlarmManager!!.setInexactRepeating(AlarmManager.RTC_WAKEUP, calendar.timeInMillis, AlarmManager.INTERVAL_DAY, mPendingIntent)
	// Restart alarm if device is rebooted
	val receiver = ComponentName(context, AlarmBootReceiver::class.java)
	context.packageManager.setComponentEnabledSetting(
	receiver,
	PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
	PackageManager.DONT_KILL_APP
	)
	}
	companion object {
	const val CHANNEL_NAME = "test"
	}
	}

view raw AlarmReceiver.kt hosted with ❤ by GitHub

	//Set the RECEIVE_BOOT_COMPLETED permission in your application's manifest. This allows your app
	//to receive the ACTION_BOOT_COMPLETED that is broadcast after the system finishes booting (this only works if
	//the app has already been launched by the user at least once):
	<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
	<receiver android:name=".ReminderServices.AlarmReceiver"
	android:enabled="false">
	<intent-filter>
	<action android:name="android.intent.action.BOOT_COMPLETED"/>
	</intent-filter>
	</receiver>

view raw AndroidManifest.xml hosted with ❤ by GitHub