'R cannot be resolved to a variable' - gen folder is empty

Question

I\'ve got an error:

R cannot be resolved to a variable

in line:

setContentView(R.layout.main);

but I can\'t r

Answer 1

I've had a similar problem. Tried everything and gen folder remained empty. It had to be with the SDK version 22. I hadn't installed the "Android SDK build-tools". I just had to install it with SDK Manager and restart Eclipse. As a member pointed on another post, the answer is better explained in this link: https://stackoverflow.com/a/16643060/1691231