How to prevent going back to the previous activity?

Question

When the BACK button is pressed on the phone, I want to prevent a specific activity from returning to its previous one.

Specifically, I have login and sign up screen

Answer 1

If you don't want to go back to all the activities on your application, you can use

android:launchMode="singleTask"

Learn more here: http://developer.android.com/guide/topics/manifest/activity-element.html