Question

I’m testing the C2DM service. I implemented my code following this GUIDE and made a little php script for sending the messages and everything runs correctly.

Then I restarted the phone and (without opening the app) sent another message, and It was received too, so the how often have I to execute the com.google.android.c2dm.intent.REGISTER for always receive messages? Once per install or more frequently?

Thanks!

Answer 1

This is the sequence of events that occurs when an Android application
running on a mobile device registers to receive messages:

1. The first time the application needs to use the messaging service, it fires off a registration Intent to a C2DM server. This registration
   Intent (com.google.android.c2dm.intent.REGISTER) includes the sender
   ID (that is, the account authorized to send messages to the
   application, which is typically the email address of an account set up
   by the application’s developer), and the application ID.
2. If the registration is successful, the C2DM server broadcasts a REGISTRATION Intent which gives the application a registration ID. The
   application should store this ID for later use. Note that Google may
   periodically refresh the registration ID, so you should design your
   application with the understanding that the REGISTRATION Intent may be
   called multiple times. Your application needs to be able to respond
   accordingly.
3. To complete the registration, the application sends the registration ID to the application server. The application server
   typically stores the registration ID in a database.

The registration ID lasts until the application explicitly unregisters
itself, or until Google refreshes the registration ID for your
application.

From Google Android C2DM