I know there are a lot of questions similar to this one. But I have tried the solutions and none are working. I thought one of the following should work:
1. Getting rid of 'import android.R' line.
2. Cleaning the project and then building it again.
Still I have the same old "R cannot be resolved to a variable" problem. The gen folder is empty.
I've had a similar issue some days ago. My R.java was not regenerated after I cleaned my project.
Here is what fixed it for me: It seems like as of SDK version 22, which I had recently downloaded, there is an additional package you have to download from the SDK manager called "Android SDK build-tools". Without this package, Eclipse will not generate R.
I installed it, restarted Eclipse and everything was working again.
I had found the solution on StackOverflow: https://stackoverflow.com/a/16643060/1691231
This usually means that you have a problem with one of your resources so R cannot be generated. Check the layout XMLs and see if one of them have a warning / error.
After removing the error please clean the project Project->clean
This may occur because of your project has errors, Please try to clear the errors, remove 'import android.R' line and Clean and build the Project.
Try this:
at first fix your layout errors.
then go to menu project-> clean and select your project
This also generally means something wrong with the build process...Have a look at the libraries tab under Java Build Path option in project properties dialog.....
Check your XML resources (especially these recently edited) for mistakes and sytax errors. When you have an error inside one of these files, the R class autogeneration will abort.
Related
I added one xml file in layout. After that this error is coming. But the problem is I haven't touched R.java file.
Now in my new activity i m going to set its content view as my newly created xml file, but when i m doing R.layout., the newly created xml is not coming in suggestion. Do anybody have any idea how to correct this.
I have cleaned my project several times but it is not working.
Delete R.java and let eclipse regenerate it, then project --> clean will fix it.
Check if you have any existing errors in your code, if yes correct it and then try refreshing and building your Project.If your Project is properly build,you will get the new xml file in suggestion
It happened to one of my Eclipse projects today. This is what fixed it mysteriously. Don't know why or how.
Changed Properties->Android->Project Build Target to a higher (different) version of Android and hit the Apply button. Then did a clean build. The problem went away.
After the above steps, I could even go back to the original Project Build Target without the problem re-appearing.
May this Help you...
I think your xml file name might be having some capital letters or some special characters..
Delete them and then try again to run the project..
Try cleaning the project this will do the work.
make sure your not importing any thing that ends with com.R
make sure your naming convention of the layout is correct
R.java file have all the resources IDs provided to resources(drawables, layouts, styles etc) either by Programmer, or generated through sdk. So check your xml files as well as your drawable folders. If any of them including wrong format it will show an error in R.java file like sometime R.java is not generating or our class file shows R.id.xxx is not found or R.class is not defined error.Then clean your project.
There must be some mistake in one of your xml files. Eclipse does not always show error messages if there is something wrong with your xml. Mostly code gets errors, in this case 'R', so you will need to go through your xml manually, it could just be a simple mistake. Good luck
I had similar problem. Cleaning project didn't solve the issue and there was no error in the code or the uppercase or spaces in file names.
The solution was going to a popup window which came when you choose PROJECT-->CLEAN and then UNcheck the "Start a build immediately" option. Clean the project. Close and reopen Eclipse and then build the project (PROJECT-->BUILD).
The question remains why simple clean and build without closing Eclipse didn't worked.
Right Click on Project->Bulid Path->Configure Build Path
ther you see error android-support-v4.jar remove this library and add library again this works fine for me.
Else
Try
Go to gen Folder delete R.java and from Project option choose Clean Project.
Very late on the scene...
I had this line mysteriously appear at the start of my imports:
import android.R;
I deleted it and shazam error was gone.
I had similar error, but when I import new project to my eclipse. and the solution was, I should check the option (copy project to work space) specially when our project has library.
i almost face the same problem again. Few minutes ago i posted a question concerning that, the
R.layout.mylayout
is not recognised by eclipse despite that, the layout folder contains my xml file and the layout folder is located inside the res folder. the answer was to delete the R.java from the gen folder and clean the project and restart the workspace.
Now, i face the same problem again despite that i followed the previous steps to solve the error but the error which is that, the
R.layout.mylayout
is not recognise still exist and there is also exclaimation mark beside the project name.
is there any other ways to solve this problem
Project - > Clean
Select "Build Automatically" so that every time you clean the project, it will be rebuilt. And yeah, make sure you are saving the file before cleaning it (I know it is weird but sometimes the errors refuse to go away until you save it and then Clean it). Make sure that there is no error in the files in the layout folder, as it sometimes prevents the auto-generation of the code in R.java
Also, make sure that your code in MainActivity.java does not have import android.R. Eclipse tends to add that when you are managing the imports.
Please check you import statements.... If you have by mistake imported the android.R , then please remove it at once.... and then clean the project and see how it works...
Run the Lint tool. Right click your project and check under Android tools. check what is the issue using that.
I recently downloaded the Android Support Package and have been using it trying to get my application, running at SDK 10, to use a GridLayout.
Anyway, I cleaned my project a few times working on this error in my XML files, and then when I went back to my classes in /src, every single reference to R.* was an error.
This has happened to me before, but it usually fixes itself, and it has not yet. Does anyone know what to do?
The R.java file is no longer in my /gen folder.
It sometimes happens when you import another project First i suggest you to build it, it will create automatically .
If it's not working then try to create new project from existing source and specify the downloaded project . It worked for me
Hope this works for you let me know..
Sometimes if there is an error in your XML files R.java won't build. Go through your XML files to make sure that everything is in order (typo, forgetting to close a bracket, etc). When you fix that it should build itself again.
You can also try Adnroid Tools>Fix Project. That may help you to create gen/R.java file
Follow following steps :
In Eclipse,
=> Right Click on Project > Android Tools > Fix Project
By this way, you can fix many common problems which can help generate R.java in gen/R.java file.
There can be several reasons why this occurs. The following I have found happen to me and I have included the steps I took to resolve them.
First step is to try and clean the project (from the Project menu option I believe)
Check there are no errors with your XML files. Sometimes this is obvious from the red 'x' that appears next to an XML filename in the Project exlporer window and sometimes it is not. If it is not obvious check the 'Errors' window (whic is founf in the 'Windows' Menu option
Failing that I have found that by disabling the automatic build option, adding some arbitrary comment to an arbitrary source file, saving the source file, clean the project, remove the comment and then re-selcting automatic build can work too.
Apologies for the approximate locations for some of the Eclipse functions but I am not currently in front of Eclipse to check.
This happens when you have an error in the res folder.
Fix the error first, then do :
Project --> Clean --> Ok
Et voila !
other answers relating to this did not help me out. Hence, I am posting a new question. I am trying to test a sample app of android that comes with their SDK. I get the error "R cannot be resolved to a variable". Looks like my R.java is not being generated. I don't know if I checked in the right place. I checked in the 'gen' folder of where I had downloaded my SDK and could not find the R.java file in the app which I am trying to test.
Could you please provide me with some ideas?
Thank you so much.
It happens when resources are not compiled. If you don't use automatic builds then just build your project. Otherwise it may happen because of some errors in resources.
I had the same problem(there was nothing under gen folder) and tried other solutions such as "cleaning project, checking if not android.R package is imported instead of mypackage.R, moving gen folder over src in java build path => order export tab and checking permissions of SDK executables" but none of them solved it.
Finally when I was checking one of the layout xml files in the res=>layout whether it has a problem or not Eclipse warned me with "The project target (Android 2.3.3) was not properly loaded" text. So I wanted to double check Android SDK Manager from Eclipse and found out that related SDK had an update. I did not see it before because it has a confusing structure with new or installed check boxes in my opinion.
When the 2.3.3 SDK updated all the problems gone...
Just clean the project and build again.
This is the most common problem I've found while developing for android.
Also try this Link for a detailed description about this issue.
Try to remove the read only in the properties of the sample sdk folder. That fix my problem i guest. Then remove the project in the eclipse. Restart eclipse. Then import it again.
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Possible Duplicate:
R cannot be resolved - Android error
I am having a issue which I have had before and I don't understand the cause. My project and code is fine as it was running yesterday. I have open Eclipse today and the whole project looks like it contains errors.
I believe it is some sort of build path issue. I don't understand why it randomly occurs? But in the code where there is R.Layout.LayoutName there is an issue... can anyone help?
I have tried cleaning and building it, I have tried importing android.R but I didn't have this before, it then gives and error and says the layout file doesn't exist.
I think I found another solution to this question.
Go to Project > Properties > Java Build Path > tab [Order and Export] > Tick Android Version Checkbox
Then if your workspace does not build automatically…
Properties again > Build Project
Are you targeting the android.R or the one in your own project?
Are you sure your own R.java file is generated? Mistakes in your xml views could cause the R.java not to be generated. Go through your view files and make sure all the xml is right!
I've fixed the problem in my case very easy:
go to Build- Path->Configure Build Path->Order and Export and ensure that <project name>/gen folder is above <project name>/src
After fixing the order the error disappears.
check your R directory ...sometimes if a file name is not all lower case and has special characters you can get this error. Im using eclipse and it only accepts file names a-z0-9_.
You want Clean Project
Like this
click on
Projects>Clean>select your project
this will help to u
Agree it is probably due to a problem in resources that is preventing build of R.Java in gen. In my case a cut n paste had given a duplicate app name in string. Sort the fault, delete gen directory and clean.
Fought the same problem for about an hour. I finally realized that I was referencing some image files in an xml file that I did not yet have in my R.drawable folder. As soon as I copied the files into the folder, the problem went away. You need to make sure you have all the necessary files present.
Save all layouts, and replace them from the previous version. Start to copy one by one and clean the project everytime, sometimes one of the layouts has something, that eclipse doesn't like. It worked for me.