Display AlertDialog from call screen in Android

I want to display an alert in the call screen when the user initiates a call.

Currently I have:

• A class MyAlert extends Activity to view and process the alert
• A class CallReceiver extends BroadCastReceiver to process the call

From CallReceiver, I launch the alert with startActivity on MyAlert. The problem is that the alert appears in my main activity, so we don't see it at the ri开发者_如何转开发ght time, but only if we open the app, which is totally useless.

If anyone has any ideas, it would help me a lot; I lost hope!

Call Screen is part of a separate application. Which means you would have to modify that source and install to get your functionality desired. The WhitePAges app I believe in fact does this..