Handling alarms with BroadcastReceiver

We met BroadcastReceiver already in Chapter 5, Interacting with Services, where we used it in an Activity to receive broadcasts from a Service. In this section, we'll use BroadcastReceiver to handle alarms set on the AlarmManager.

BroadcastReceivers can be registered and unregistered dynamically at runtime like we did in Chapter 5, Interacting with Services, with Service, or statically in the Android manifest file with a <receiver> element, and can receive alarms regardless of how they are registered.

It is more common to use a statically registered receiver for alarms, because these are known to the system and can be invoked by alarms to start an application if it is not currently running.

Let's implement a static defined BroadcastReceiver that is able to dispatch an SMS to a phone number when an alarm sounds. First we will define our BroadcastReceiver in the manifest file:

<receiver android:name=".chapter6.SMSDispacther">
  <intent-filter...