On the Android project, suddenly the R class could not find a workaround for the existing resource file

Project code open in the morning, the afternoon when suddenly prompted R class can not find the existing layout file, so try a variety of methods, clean Ah, restart Ah, are invalid, and then went to the Internet search, encountered the problem of many people.

See that there is such a workaround, delete the imported ANDROID.R package, go to check their own code, sure enough there is such a row, after deletion, the problem is resolved.

But it's strange what this ANDROID.R is, and the answer is that it is a system resource class that, if imported, conflicts with the R class of the local project file, resulting in errors, missing layout files, and so on.

Hope to be helpful to everyone.

On the Android project, suddenly the R class could not find a workaround for the existing resource file