Questions Regarding Handling of Received SMS

I have managed to suc开发者_运维问答cessfully write a little test app that can receive and send SMS, but got a couple of questions. (That's 'cos part of the code I copied from elsewhere and I would like to understand better).

1. In my AndroidManifest as well as the sub-class of BroadcastReceiver, there is reference to the string literal "android.provider.Telephony.SMS_RECEIVED". However, I couldn't find any reference in the API that mentions this. Could someone point me to some reference that lists/explains these?

2. As part of getting the message from the Intent, I did this:

   Object[] pdus = (Object[]) intent.getExtras().get("pdus");

Again this question is related to the use of hardcoded string literal. Where is the string "pdus" listed and described?

Thanks in advance!

The reason why you are not finding those things is because they are not part of the SDK and therefore are not designed to be used by applications. It is possible that those Intents will be altered in future releases of Android, or perhaps not used on certain devices.