Android - How to regenerate R class? [duplicate]

Answer 1

You can just modify any xml files in /res folder and even just add a space and save, it will be regenerated.

Answer 2

In my case it was an improperly named XML file that caused my R file not to rebuild. This did not show up in the package explorer, but it was shown in the LogCat. Look out for any warnings there about your res files. No matter how many times you clean your project, the R file will not rebuild until those errors are taken care of.

Answer 3

I have tried all the solutions above. But they unfortunately it did not solve my problem. My R.java was gone as soon as I pasted a new picture to my drawable folder. After reading the answers for this question I tried to delete the icon I have previously pasted (while Build Automatically Enabled) and everything was fine afetr. Hope this will help someone!

Answer 4

I have a problem that the findViewById(R.id.edit_text) but return a TextView not a EditText. I think the problem is the R.id class has wrong id number, then, i clean the project then its works fine.

Answer 5

If you use Intellij IDEA you can click Build - Rebuild Project

Answer 6

Mostly a problem with an invalid layout file. Open the 'Problems' view and look for erros in XML layout files. Fix them and the R class will be recreated.

In my case there wasn't a real error. The problem view showed an error in a xml layout. The editor showed the xml error too. Just reformatting the xml using the auto formatter with 'ctrl-f' 'fixed' the xml 'error' and the R class was recreated.