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

First:

import android.content.pm.PackageManager.NameNotFoundException;

and then use this:

PackageInfo pInfo = null;
try {
     pInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
} catch (NameNotFoundException e) {
     e.printStackTrace();
            }
String versionName = pInfo.versionName;