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.
It seams that I missing the R file, this is a common error and usually I have solved by cleaning the projects, using android tools fix project properties and restarting eclipse.
Now I have installed the new android developer tools eclipse and after importing the project I have this error in eclipse:
Errors occurred during the build.
Errors running builder 'Android Pre Compiler' on project 'MyProject'.
java.lang.NullPointerException
and the R file is not generated so it is missing.
The project is a library project. Thanks
Sometimes if you have errors in an XML file, it will stop the project from building correctly and the resources (project.R) file won't be created properly. You will also need to make sure that you are importing your resource file and not the one from android.R
If you've changed the project build target or minSdkVersion, you might have XML nodes in one of your layout files that isn't supported by the SDK you are using which will stop it from building. That's also worth checking
Go to Project and hit Clean. This should regenerate your R.java file.
Also get rid of any import android.R.* statements and then do the clean up as mentioned.
Otherwise, XML resource under layout may not having the correct naming convention or might be having some capital letters.
Try changing them to lowercase and make sure your layout.xml files don't contains errors.
Clean the project because the project may have trouble finding the name of a resources, it really sucks that i constantly have this problem when adding new image..
I am not able to get back my R.java file after cleaning my project.
Please suggest me a solution which help me in this matter..
thanks in advance...
this can happen from one of two reasons:
you are not auto-rebuilding your project. (can be fixed in the settings).
you have a property within your project with and illegal name (such as files with capital letters).
fix this and the project will rebuild with no problems.
Try building your project by selecting your project--> Build Project.
remove the Build Automatically setting from your projects tab of eclipse.
Try building them manually.
The eclipse is not able to build R.java . There might be some problem in your xml layouts. Check them out.
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 !
After I added some .png files into my Project Workspace drawable folder I refreshed my drawable folders in Eclipse and the newly added files showed up. But when I tried to access those resources using R.drawable.xyzimage, xyzimage although in the folder could not be resolved.
So I did a Project Clean and guess what after this clean R.java is totally gone and all my classes accessing resources using R.java is showing all sorts of error and Eclipse won't let me run the code anymore.
I have backup of my source code but I want to explore if R.java can be regenerated and how?
Thanks for all the help.
Try Project->Clean in Eclipse. In my limited experience if R.java is not being automatically created then there is an error somewhere in your xml. Triple check everything.
You have to build the project to be able to use the newly added resources.
Cleaning a project removes all auto-generated files. Building the project it should automatically create them. When you Clean a project, there's an option to start a build immediately after clean up.
Here's a few things you can try (did the same procedure after manually deleting the "gen" directory.
After you have deleted the gen directory, go to Project > Clean ...
You should have errors indicating that R cannot be resolved to a variable. Right click on your project from the Package Explorer and select Build Project. Be sure Build Automatically option is turned off (uncheck in Project > Build Automatically).
Errors regarding R should have now disappeared. Now, perform a Project Clean once again. All errors should be gone.
Let me know if this works for you.
Here is what the problem was. I added those new png images to the project and android has rules as to what characters are allowed in the names of these images. Once I changed the uppercase letters in the image name, it was back on track again and Build Automatically generated the R.java file and all errors were gone. Eclipse console is the place where I found all the errors related to my resources.
Thanks Guys....I tried your solutions but my error was something specific which was due to my image naming convention so this is the way I fixed it.
I would agree this is usually a XML problem but moreover that it is something within your res folder that is the problem and may be highlighted with a red cross after the clean attempt.
I have just had this problem and it was because I had created my own folder called 'data' within res folder. After the clean it had a little red cross against it. I removed this folder and R built again.
Regards,
Mark
Several things you should check in your project:
Check the Problems tab in your Eclipse IDE. Are you sure that you did not introduced building problems while making changes with drawables? To check that you need to check xml source of affected layout and see if something is marked red.
In File explorer go to the directory where your Android project is. Check that you have file default.properties (.classpath, .project and AndroidManifest.xml should be there). If default.properties is missing it may be easily replaced by correct version.
Which is the Android version you are working with? If that is 1.5 or lower be sure that in the res directory you have directory named drawable, not drawable-hdpi, drawable-mdpi and drawable-ldpi. Last three are valid for version 1.6 and higher.
Right click on your project in Package explorer in Eclipse. You will get a number of options. Go to Android Tools-> Fix Project Properties so see if that helps.
I had an invalid jpg in my res/drawable folder. I removed the jpg and it worked.
I had this problem on my Mac too and I think it could be good to know for all Mac users how I managed to solve this error.
I had a .DSStore file automatically imported to my project inside the res directory and when I removed it and rebuilt the project all went well.
Everytime you clean the project and it rebuilds, it imports
import.android.R
so, delete this import and remove all errors from xml files. It will work.
This happens to me if I move my project to a new location. I have found that the answers above didn't fix my problem, but that creating a new project and importing the source did.
This may be simple but check to make sure you don't use
import android.R;
If you add an external resource file with capital letters for example
"Hello.png or WelcomeSound.mp3 etc etc" like if you add upper case letters and clean your project you'd surely loose your R.java file. So if you already lost it, either rename the file externally and then clean your project or else right click on the project Refractor->Rename and then rename your file with all letters in lower casing. Next, delete the 'gen' folder in the project explorer and now right click and "Build Project". If Build Project option is grayed out, go to Project-> Deselect "Build Automatically" option.
Regards,
Kshitij Thube
Check at the Console View If there in message Error, It will Help you to find out the source of the probleme.
I had i similar probleme and i find out that the probleme was from the pic name even if the name respect the Syntax so I change it to img1 and it worked fine.
Try editing one line of code in your project, then build the project once more.
Another thing: never try to run an application with the texteditor opened with a xml file. That will create a wierd run configuration that can only be fixed by project clean-up and sometimes can make the xml file to vanish (happened to me twice already).
All my R.* files stopped working after I did a Project->clean in Eclipse. The issue was that I backed up a XML file attached to one of my activities in the layout directory. This causes errors in every activity of my project.
After deleting the file I still had R errors in one of my Activities and it only was resolved after I tried importing different files and then deleting them. I actually made no change to the previous imports but for some reason deleting them all and re-pasting them fixed it.
I have got the same problem after lots of cleaning and building project again and again. I found that on console there is this error:
res/drawable-hdpi/Blue Blank.png: Invalid file name: must contain only [a-z0-9_.]
and this is not appearing as an error in xml. I changed the name and save the file, clean project and build. Now it's working. My suggestion check your res folder and name of files you use in it and name only [a-z0-9_.].
Delete related tag in xml, save xml, clean project, build project. Now again put that resource in xml and save!
Check your file in drawable folder ensure that all are resource file (image) remove unwanted file Like thumb.db. Remove those all files and check again
Make sure your png files have lowercase names. That is what kept throwing mine out, because I capitalized the first letter, or I used an unallowed non alpha numeric in the naming. Check that before destroying any of your code.
just check your image folder (usually created res > drawable files) and be sure dont use capital letters on .png files, every type must be in small letters then you can find again your R.java under the gen file folder
i removed 'import android.R;' then commented out the offending lines, then did a build, ok
then i removed the comment and it fixed it
I had the same problem when I cleaned my project. I got crazy to solve it, I searched and searched but solved it in my way.
First of all, delete all needless files in your /res folder. I had some notes in it, I took them to another project that I don't work on it and build the project manually. It worked! Try this I'm sure it will help.
Good developing!
Was there an XML file with the naming convention of "somthing.out.xml" generated? If so you should delete this file (an unwanted file of this name can cause major problems for your somthing.somthing.R file import).
In some versions of eclipse (I know eclipse javaEE does this for sure), running the project while viewing an XML file will create a file called filename.out.xml in your res->layout folder. You must delete this generated file if this has occurred otherwise you wont be able to get the java.R file to import.
Try Project -> check Build Automatically
If you are using 64-bit Ubuntu, try to install the 32-bit libraries (ia32-libs)
$ sudo apt-get install ia32-libs
it worked for me
This exact same thing happened to me. coincidentally I needed to update my adk that day, so i did so and after restarting eclipse it worked again. My recommendation would be to build the project and restart eclipse. It is not due to any error in your code.
I read and tried many of the above after simply doing a clean on one project. Eclipse would not build anything afterwards.
Fortunately I had last-nights backup of the workspace and my source is copied in from VS 2010.
No more cleaning!
Delete your project from workspace witout source deleting and then import it into workspace.
RightClick on your Project -> Delete /Don't select "Delete project content on disk (cannot be undone)"/ -> Ok
File -> Import -> General -> Existing Projects into Workspace -> Brouse -> /Look for your workspace(!) folder/ -> Ok -> /your cleaned project will be automatically checked/ -> Finish
I had the dreaded missing R problem yesterday with Eclipse Juno after a routine clean. StackExchange is full of suggestions and extensive googling revealed only the usual suspects (XML naming conventions problems, etc) none of which seemed to apply directly, although it is certainly possible I missed something.
The best summary comprehensive list of possible causes and fixes was here:
http://www.techrepublic.com/blog/software-engineer/a-comprehensive-troubleshooting-guide-for-androids-r-cannot-be-resolved-error/
One useful tip there was to try to create and run a simple "Hello World" in my workspace. If that does not run, the setup is corrupted. My Hello World was just as full of errors as my custom app.
The solution that worked for me (perhaps great overkill but nothing else worked) was to completely uninstall Android SDK and delete Eclipse (Juno), download Eclipse for Developers (Kepler) and reinstall Android ADT plugin and ADK and recreated my AVDs using the latest "compile with" version in options.
So far so good, although I am recreating the app from scratch. I will be more cautious about using clean from here on.
I have same problem occur just now I renamed invalid png file like *demo.1.png as demo.png * and its work.
Proven successful method, check the file (AndroidManifest.xml) and delete all comments in it, and make sure there are no errors in this file, I tried and did work with me.