Android AlarmManager allows you to access system alarm.
By the help of Android AlarmManager in android, you can schedule your application to run at a specific time in the future. It works whether your phone is running or not.
The Android AlarmManager holds a CPU wake lock that provides guarantee not to sleep the phone until broadcast is handled.
Android AlarmManager Example
Let's see a simple AlarmManager example that runs after a specific time provided by user.
You need to drag only a edittext and a button as given below.
The activity class starts the alarm service when user clicks on the button.
Let's create BroadcastReceiver class that starts alarm.
You need to provide a receiver entry in AndroidManifest.xml file.
Let's see the full code of AndroidManifest.xml file.