I'm new to Android and stuck with this error. I just imported an existing project to eclipse.
Plz help me to solve this. I googled a lot. But i can't solve this.
Thanks in advance
possible problems:
1- its possible that you have 2 resources that have the same name!
2- In one of your files you must have imported a wrong R package...
3- or you have a resource (like an image) that has the same name of a resource in android SDK files
4- try to rebuild and cleaning the project
I think your problem is No.2.. try to delete every import statement that has imported R package, then import the suggested R package yourself
Probably try to clean the project if you are using eclipse.
Go to Project -> Clean. Select your project.
Also keep Build Automatically option in Project menu checked for future changes.
RK
http://ctrlaltsolve.blogspot.in
I have map Project in Eclipse IDE and I Cleaned It From Project Menu.It deleted mY BIN Folder and also Gen Folder.Now I Have tried Much BY Build Manually and also from Android Toold To Fix Project Properties But It is Not fixing the Problem and In Source Files R is Red underlined and Bin and Gen Folder are Not Being Created again.Please any oNe Help me to To Get Out OF this issue.
There may be Some Reasons :-
1.from Project-> checked Build Automatically.
2.There Should not any error in your xml otherwise R file will not build automatically.
3.Refresh the project & Restart eclipse.
First backup(e.g. zip) your whole workspace before you start experimenting. Then try to remove IDE specific files e.g. .project .classpath and setup it again. If it fails create new project with similar configuration and simply copy your libraries and source code into new project. Eclipse IDE is pure magic sometimes.
If you have imported this project, then try import as a general project, not as android project. then in build path see if all libraries are present, then run as android application
you have to try till you succeed process.
Try following steps:-
Make sure there is no error any any of your .xml files .. check in
Problem section..
Make sure all your impoert are correct, Eclipse sometimes do import
android.R; on its own, so remove that..
If that doesnt succed make some changes in Manifest file say remove a
word save it then again add that word save it.. I know it doesnot
make sence as code but making changes in Manifest files rebuilds the
workspace an so is the auto generated files. then clean build your
project.
Restart Eclipse as last resort..
try the following steps to help us
remove if imported import android.R; and after like example if your application package name is com.example.project you need import like import com.example.project.R;
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.
My PC went to sleep while battery was low. But when it recovered I found R.java file missing from my gen folder. My entire application is under crash.
The error is shown below:
If you recently added a new resource file and happen to use upper case letters in the file name, change the file name to lowercases and rebuild your project. That is what happened to my project.
The R.java file should be regenerated every time you do a rebuild of your project.
Clean the project,
Go through your code and remove all references to android.R.*
So when your R.java is corrupt or missing Eclipse tries to be helpful and thinks that the references in your code for R.something are missing the import file and inserts the android.R.* to your import list.
If you are using IntelliJ it has a rebuild R.java command.
If it is still missing then it means that something in your code is preventing it from being built. Pay attention to resource file names etc. Usually you can sport these naming problems in console view of eclipse
There are possible chances, you have a problem in your layout xml or in your code.
Try looking at file that you had open in your eclipse when it went to sleep, and code snippet that you were working at.
Edit:
R (resource file) regenrates at every rebuild of your project. For some error in your project your project wasn't able to build that why your R file is missing. All that you need to do is to fix issue in your files, code and xml files.
I got the same issue. Nearly I spent whole day working on it to figure out the reason and tried all the 100 solutions provided in the blogs. But nothing helped!!! After setting up a new workspace I figured out. Remove unnecessary libraries in your project. You can check this by Project-> right click-> properties-> Android-> and remove unnecessary added libraries. It worked :) Hope it helps some one.
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.