"cannot resolve symbol R" in Android Studio

android, android-studio, r.java-file

Solution

I had this this issue too. A simple 'gradlew clean' and 'gradlew build' did the trick.

Click on Build->Clean Project and that will perform a gradle clean

Problem

In every instance in all of my classes where I reference `R.id.something`, the `R` is in red and it says "cannot resolve symbol R". Also every time there is `R.layout.something` it is underlined in red and says "cannot resolve method setContentView(?)". The project always builds fine. It is annoying to see this all the time. I have read many other questions on here about something similar but most involved importing projects from Eclipse. I am using what I believe to be the most recent version of Android Studio and the project was created with Android Studio and worked without any "cannot resolve R" problems. I would like to know what causes this if anyone knows.

Original source

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