What's the easiest way to force Idea to generate the R.Java file?

Question

I am trying to run Android sample applications using intellij idea and R.Java file is missing form notepad samples source directory.

Answer 1

Make sure you have a gen folder in your project root. If you don't, make one yourself.

Answer 2

Fix all errors appear on .xml files. R.java will be re-appeared

Answer 3

Also make sure to check your imports. Sometimes when your IDE (eclipse & intellij as well) cannot find your generated R class and auto-imports android.R.

import android.R kills everything you are doing in your generated sources!

Cost me 30min of my life...