Eclipse error R cannot be resolved to a variable

Question

I am getting this classic error in Eclipse IDE  I am bored of Eclipse s bugs  They driving me mad   I almost tried everything which suggested as solution  by Googling   None of them worked   My project was working normally but not code changes   I see that my code changes does not acting on my app  on AVD  then I cleaned my project  under Project  gt  Clean      R java file was gone and res folder was empty   Now I am getting that error  R cannot be resolved to a variable   What should I do   And also I tried to delete project and create again with Android Project from Existing Code I ve backed-up before  It already gives same error after cleaning   Any ideas would be appreciated

User · Accepted Answer

I assume you have updated ADT with version 22 and R.java file is not getting generated.

If this is the case, then here is the solution:

Hope you know Android studio has gradle building tool. Same as in eclipse they have given new component in the Tools folder called Android SDK Build-tools that needs to be installed. Open the Android SDK Manager, select the newly added build tools, install it, restart the SDK Manager after the update.

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User · Answer

Try to delete the import line import com your package name app R  then  any resource calls such as mView   View  mView findViewById R id resource name   will highlight the  R  with an error  a  Quick fix  will prompt you to import R  and there will be at least two options     android R your package name R   Select the R corresponding to your package name  and you should be good to go  Hope that helps

User · Answer

In addition to install the build tools and restart the update manager I also had to restart Eclipse to make this work

User · Answer

I m not posting this as an answer but a confirmation to Paresh s accepted answer  I recently updated SDK tools to Revision 22 and I noticed my code changes was not being affective on the device i m testing at all  Such as the url I was using  I was getting errors for connection time out regarding the url I was  previously  using  Therefore I cleaned the project and built again only to find out that autogenerated R java file is missing    After reading Paresh s answer and checking what s going on with my sdk manager this is what I saw    SDK Build-tools 17 was not installed and there was already a new update to SDK tools even though it does not mention any change related to this problem in the changelog  this update brought back my R java file and the related problems were gone after an eclipse restart and final clean rebuild on the project

User · Answer

I had a fully working project to which I was doing a minor change when this occured after updateting the SDK  Eclipse updated the SDK and the ADT but I could still not build the project  Exlipse said there were no further updates available   The problem persisted until I manually uninstalled the ADT from eclipse and re-installed it   Only then would my project build  I had restarted eclipse inbetween each step

User · Answer

The R file can t be generated if your layout contains errors   If your res folder is empty  then it s safe to assume that there s no res layout folder with any layouts in it  but your activity is probably calling setContentView and not finding anything -- that qualifies as a problem with your layout

[android] Eclipse error: R cannot be resolved to a variable

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