R cannot be resolved to a variable

Question

I would like to fix this error

R cannot be resolved to a variable

I looked up many answers, but I could not get the right one;

Answer 1

Tip: update SDK and all utilities else one time. It helped to me.

Answer 2

I had the same issue and main reason why R.java was not re-generated is errors in any of the files in the project. Once we fix those the R.java should get generated.

Answer 3

Just look in to your header files there will be:

import somefile.R;

Just remove that line and that's it.

Answer 4

I had the same problem. I didn't have any lines stating "import something.R". Cleaning and rebuilding also didn't solve the issue.

It turned out to be because of the name of a layout xml file. Those files can only contain lowercase letters, or numbers, or underscores. When I changed the filename (and everything that refers to it) from myLayout.xml to my_layout.xml, everything worked.

Answer 5

Nothing mentioned above worked for me. However, I fixed it myself.

Solution:

If you've any other files except activity_main.xml / main.xml inside app_name/res/layout remove it and try clean and build.

Note:

The unwanted files or (rather used later) files inside app_name/res/layout would be *.out.xml. Remove the same.

Answer 6

what did it for me...

when i checked my project properties file (/project_root/project.properties), it had a reference to an old android version target which i no longer had installed

# Project target.
target=android-15

as soon as I changed this to say 17, it worked perfectly, soon as the file was saved my gen folders were built and inflated.

# Project target.
target=android-17