Characteristics of AlarmManager:<\/h4>\n
1. AlarmManager schedules the intents to trigger at a specific time or time intervals. This is useful for setting reminders, notifications, or performing time-based operations in your app, ensuring they run at the precise time you intend.<\/p>\n
2. AlarmManager provides the application with the ability to run at a specific time. Even if the application is not running or your device falls asleep still the alarm can trigger to start your application. This feature is crucial for tasks like sending timely notifications or initiating background processes without user intervention.<\/p>\n
3. AlarmManager is used to minimise the requirement of many resources. By scheduling tasks efficiently, it reduces the need for constant background activity, thus conserving battery and system resources.<\/p>\n
4. AlarmManager allows you to operate with the broadcast receivers to start or stop specific services. This makes it easy to manage and automate service operations, enhancing the functionality and responsiveness of your application.<\/p>\n
5. AlarmManager holds your CPU clock and waits until we force it to stop or reboot our device. This ensures that the scheduled alarms are reliable and are executed as expected, providing a consistent user experience.<\/p>\n
Now let\u2019s see an example of how you can initialise AlarmManager and use it in your project.<\/p>\n
Code:<\/strong><\/p>\n There are several methods that we can use to implement the AlarmManager properly in our projects. Each method has its significant use, and you are recommended to look at the purpose of each method before proceeding with the implementation.<\/p>\n Now let\u2019s see how you can implement AlarmManger and the above-seen concepts through an android app. We will try to develop an app using which you can schedule alarms for a particular time. Follow the below steps:<\/p>\n 1:<\/strong> Start your Android Studio and click on Create a new Project.<\/p>\n 2:<\/strong> Select an empty activity, provide project name, select API level 22 and then click finish.<\/p>\n 3:<\/strong> First of all, open your AndroidManifest.xml file and then paste the below code.<\/p>\n Code: AndroidManifest.xml<\/strong><\/p>\n 4:<\/strong> Open your activity_main.xml file and paste in the below code there.<\/p>\n Code: activity_main.xml<\/strong><\/p>\n 5:<\/strong> Now, in your MainActivity.kt you need to set up the AlarmManager and the pending intent.<\/p>\n Code: MainActivity.kt<\/strong><\/p>\n Run your application by using the top right play button and then notice the output.<\/p>\n The TechVidvan Alarm App will look like below.<\/p>\n You can now select the time where you want your alarm to get scheduled.<\/p>\n\/\/creating the AlarmManager object\r\n val alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager\r\n\r\n \/\/Creating an intent to the MyAlarm Class\r\n val intent = Intent(this, MyAlarm::class.java)\r\n\r\n \/\/setting up a pending intent\r\n val yourPendingIntent = PendingIntent.getBroadcast(this, 999, intent, 0)\r\n alarmManager.setRepeating(\r\n AlarmManager.RTC,\r\n timeInMillis,\r\n AlarmManager.INTERVAL_DAY,\r\n yourPendingIntent\r\n )\r\n<\/pre>\n
Methods involved in Alarm Manager<\/h3>\n
\n\n
\n Method Name<\/b><\/td>\n Purpose of the Method<\/b><\/td>\n<\/tr>\n \n set(type: Int, triggerAtMillis: Long, operation: PendingIntent!)<\/span><\/td>\n The set() method is used for setting alarms.<\/span><\/td>\n<\/tr>\n \n setExact(type: Int, triggerAtMillis: Long, operation: PendingIntent!)<\/span><\/td>\n The setExact() method is used to set alarms specifically at a specific time.\u00a0<\/span><\/td>\n<\/tr>\n \n setRepeating(type: Int, triggerAtMillis: Long, intervalMillis: Long, operation: PendingIntent!)<\/span><\/td>\n The setRepeating() method is used to set repeating alarms on your device.<\/span><\/td>\n<\/tr>\n \n setTimeZone(timeZone: String!)<\/span><\/td>\n The setTimeZone() method is used to set a new or default timezone for your alarms.\u00a0<\/span><\/td>\n<\/tr>\n \n setWindow(set_type: Int, StartMillis: Long, LengthMillis: Long, task_operation: yourPendingIntent!)<\/span><\/td>\n The setWindow() method is used to set a specific time slot during which your alarm should trigger.\u00a0<\/span><\/td>\n<\/tr>\n \n setAndAllowWhileIdle(type: Int, triggerAtMillis: Long, operation: PendingIntent!)<\/span><\/td>\n The setAndAllowWhileIdle() method sets alarms that can trigger even in low battery idle modes.\u00a0<\/span><\/td>\n<\/tr>\n \n getNextAlarmClock()<\/span><\/td>\n The getNextAlarmClock() gives us the details of the next alarm that is scheduled.\u00a0<\/span><\/td>\n<\/tr>\n \n cancel(operation: PendingIntent!)<\/span><\/td>\n The cancel method is used to discard the alarm matching the specified pending intent.\u00a0<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Implementation of Alarm Manager in Android<\/h3>\n
<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<manifest xmlns:android=\"http:\/\/schemas.android.com\/apk\/res\/android\"\r\n package=\"com.techvidvan.techvidvanalarm\">\r\n\r\n <application\r\n android:allowBackup=\"true\"\r\n android:icon=\"@mipmap\/ic_launcher\"\r\n android:label=\"@string\/app_name\"\r\n android:roundIcon=\"@mipmap\/ic_launcher_round\"\r\n android:supportsRtl=\"true\"\r\n android:theme=\"@style\/Theme.TechVidvanAlarm\">\r\n <activity android:name=\".MainActivity\">\r\n <intent-filter>\r\n <action android:name=\"android.intent.action.MAIN\" \/>\r\n\r\n <category android:name=\"android.intent.category.LAUNCHER\" \/>\r\n <\/intent-filter>\r\n <\/activity>\r\n <\/application>\r\n\r\n<\/manifest>\r\n<\/pre>\n
<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<LinearLayout xmlns:android=\"http:\/\/schemas.android.com\/apk\/res\/android\"\r\n xmlns:tools=\"http:\/\/schemas.android.com\/tools\"\r\n android:layout_width=\"match_parent\"\r\n android:layout_height=\"match_parent\"\r\n android:orientation=\"vertical\"\r\n tools:context=\".MainActivity\">\r\n\r\n <TextView\r\n android:layout_width=\"match_parent\"\r\n android:layout_height=\"wrap_content\"\r\n android:text=\"TechVidvan Alarm App\"\r\n android:textStyle=\"bold\"\r\n android:textSize=\"30sp\"\r\n android:gravity=\"center\"\r\n android:textColor=\"#000000\"\r\n android:layout_marginBottom=\"30dp\"\r\n android:layout_marginTop=\"20dp\"\r\n android:id=\"@+id\/title\"\/>\r\n <TimePicker\r\n android:id=\"@+id\/timePicker\"\r\n android:layout_width=\"match_parent\"\r\n android:layout_margin=\"20dp\"\r\n android:layout_marginTop=\"50dp\"\r\n android:headerBackground=\"#8BC34A\"\r\n android:numbersBackgroundColor=\"#000\"\r\n android:numbersTextColor=\"#ffffff\"\r\n android:numbersSelectorColor=\"#8BC34A\"\r\n android:layout_height=\"wrap_content\" \/>\r\n <Button\r\n android:id=\"@+id\/setAlarmButton\"\r\n android:layout_width=\"wrap_content\"\r\n android:layout_height=\"wrap_content\"\r\n android:layout_marginTop=\"30dp\"\r\n android:layout_gravity=\"center\"\r\n android:backgroundTint=\"#000000\"\r\n android:textColor=\"#8BC34A\"\r\n android:textStyle=\"bold\"\r\n android:text=\"Schedule Alarm\" \/>\r\n\r\n<\/LinearLayout>\r\n<\/pre>\n
package com.techvidvan.techvidvanalarm\r\n\r\nimport android.app.AlarmManager\r\nimport android.app.PendingIntent\r\nimport android.content.BroadcastReceiver\r\nimport android.content.Context\r\nimport android.content.Intent\r\nimport android.os.Build\r\nimport android.os.Bundle\r\nimport android.util.Log\r\nimport android.widget.Button\r\nimport android.widget.TimePicker\r\nimport android.widget.Toast\r\nimport androidx.appcompat.app.AppCompatActivity\r\nimport java.util.*\r\nclass MainActivity : AppCompatActivity()\r\n{\r\n \/\/declaring variables\r\n lateinit var setAlarmButton: Button\r\n lateinit var timePicker: TimePicker\r\n\r\n override fun onCreate(savedInstanceState: Bundle?)\r\n {\r\n super.onCreate(savedInstanceState)\r\n setContentView(R.layout.activity_main)\r\n\r\n \/\/binding the timePicker variable with the TimePicker View\r\n timePicker = findViewById(R.id.timePicker)\r\n \/\/binding the setAlarmButton variable with the Schedule Alarm Button\r\n setAlarmButton = findViewById(R.id.setAlarmButton)\r\n\r\n \/\/adding on click listener on our setAlarmButton\r\n setAlarmButton.setOnClickListener {\r\n\r\n \/\/creating an instance of the calendar class\r\n val calendar: Calendar = Calendar.getInstance()\r\n\r\n \/\/setting up the calendar\r\n if (Build.VERSION.SDK_INT >= 23)\r\n {\r\n calendar.set(\r\n calendar.get(Calendar.YEAR),\r\n calendar.get(Calendar.MONTH),\r\n calendar.get(Calendar.DAY_OF_MONTH),\r\n timePicker.hour,\r\n timePicker.minute,\r\n 0\r\n )\r\n }\r\n else\r\n {\r\n calendar.set(\r\n calendar.get(Calendar.YEAR),\r\n calendar.get(Calendar.MONTH),\r\n calendar.get(Calendar.DAY_OF_MONTH),\r\n timePicker.currentHour,\r\n timePicker.currentMinute, 0\r\n )\r\n }\r\n\r\n \/\/calling the setAlarm method with time in milliseconds\r\n setAlarm(calendar.timeInMillis)\r\n }\r\n }\r\n private fun setAlarm(timeInMillis: Long)\r\n {\r\n \/\/creating the AlarmManager object\r\n val alarmManager = getSystemService(Context.ALARM_SERVICE) as AlarmManager\r\n\r\n \/\/Creating an intent to the MyAlarm Class\r\n val intent = Intent(this, MyAlarm::class.java)\r\n\r\n \/\/setting up a pending intent\r\n val yourPendingIntent = PendingIntent.getBroadcast(this, 999, intent, 0)\r\n alarmManager.setRepeating(\r\n AlarmManager.RTC,\r\n timeInMillis,\r\n AlarmManager.INTERVAL_DAY,\r\n yourPendingIntent\r\n )\r\n\r\n \/\/displaying the user that the alarm is scheduled\r\n Toast.makeText(this, \"You Alarm is Scheduled\", Toast.LENGTH_SHORT).show()\r\n }\r\n\r\n \/\/creating the MyAlarm class extending properties from BroadcastReceiver\r\n private class MyAlarm : BroadcastReceiver()\r\n {\r\n \/\/calling the onReceive Method when the alarm is triggered\r\n override fun onReceive(\r\n context: Context,\r\n intent: Intent\r\n ) {\r\n Log.d(\"TechVidvan\", \"Your Alarm is triggered\")\r\n }\r\n }\r\n}\r\n<\/pre>\n![\"Android](\"https:\/\/techvidvan.com\/tutorials\/wp-content\/uploads\/sites\/2\/2021\/08\/App_Output_1-3.jpg\")
<\/a><\/p>\n