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 · 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 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

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 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

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

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

Examples related to android

Examples related to eclipse