title: Android R.java problems. R.java file does not update?
body: <p>I am having a problem with the gen/r.java file.  When I create or edit files in resources such as layout /values/strings.xml  e.t.c  the r.java file does not update.  I have followed a tutorial and it for some reason won't update.  There are no errors in the xml file.  </p>
  
  <p>I have heard people say "use clean/build" e.t.c but this just removes the r.java file and I am unable to get it back after many attempts. This results in me having to redo the whole project again just to get the gen file back. Why is this happening?</p>