Cannot resolve R to variable after Android studio update

Question

I just updated my android studio and now all my resources are errors!

• I have debugging and debugging, but to no avail.
• All my xmls files are fine,
• All lines begin in lower case.
• I also restarted the program

Answer 1

This is a known bug in the latest version of android studio 0.1.6. Google proposed a temporary solution to the problem until they can track the problem and fix it in the next version. disable external builds in settings> compiler.

Answer 2

You seem to have updated the Android SDK Tools to version 22, but you may not have updated the Android SDK Build-Tools to the latest version. Update it from sdk manager and restart. See this answer for a similar question: Eclipse giving an error, missing R.java file after a recent update . Hope this helps

Answer 3

Have you tried the build button in android studio? .... use it and click "rebuild project", see what happens.

Answer 4

"Settings" / "Settings" → "Compiler" Check the box "Use external assembly" if you are using gradle and uncheck the box "Use external assembly" if you are NOT using gradle.

Sources: https://code.google.com/p/android/issues/detail?id=56843 https://code.google.com/p/android/issues/detail?id=56531

Answer 5

This error went away for me when I just built a project (Ctrl + F9).

Answer 6

I have the same problem, all you have to do is click "Build> Rebuild Project" before each launch or debugging. I hope this error is fixed as soon as possible.

Answer 7

Updated tools "Tools → Android → SDK Manager" are updated and the SDK to the latest version.

Also updated android: targetSdkVersion = "18" to the latest version in AndroidManifest.xml and it solved the problem.

Answer 8

In Android Studio, can not resolve R error due to build.gradle the minmum sdk file and minSdkVersion and targetSdkVersion sdk platform must be installed, and if updates are updated first. Another thing buildToolsVersion and android.support:appcompat needs to be clear so that no ambiguity is detected. You can install them manually from build.gradle or from File -> Project Structure -> app and Flavors . Some other causes of the R error cannot be caused by an error in the .xml file. In most cases, I solve my problem using these methods.