How to get the build/version number of your Android application?

Question

I need to figure out how to get or make a build number for my Android application. I need the build number to display in the UI.

Do I have to do something with

Answer 1

Slightly shorter version if you just want the version name.

String versionName = context.getPackageManager()
    .getPackageInfo(context.getPackageName(), 0).versionName;