This is my third time setting up my android env in eclipse (for different computers).
This time I cannot get it to work, something didnt get set up correctly or I'm forgetting something.
gen folder is not getting generated and of course no R.java file. I have searched online everywhere and cannot find a solution to this problem. That applies to creating a new project and using android sample projects.
No I do not have import android.R, restarted eclipse mult times, did clean project, build project, no new updates to be installed..
Thanks in advance, any help would be great!
This is usually due to a quirk in Eclipse. Often, but not always, it is solved by this magic invocation: Pressing ctrl+shift+O, then "Project Clean" (uncheck "Build automatically" first), then "Build All" and see if it works.
TRy closing and starting eclipse again.
Related
I'm trying to learn how to develop an Android App from scratch using Eclipse, but I keep running into the "R cannot be resolved into a variable" error. I tried everything from completely removing Eclipse and downloading it again, to deleting my project and workspace and starting over, but I just cannot get away from this error. The thing is, it's coming up without me even doing anything. I just start a new Android project and it opens with this error so I can't move forward in learning this stuff.
Any ideas on what I can do? Keep in mind I'm at the absolute beginning of learning how to work with Eclipse, so if you have a possible solution, I'd really appreciate a step-by-step answer.
Thank you!
EDIT: As it turns out, I didn't have any of the build-tools installed. I remember installing them but I have no idea what happened and they were just not listed as installed. After re-installing, I'm good to go. Thanks for the help everyone!
Right click on your project and clean it, if there are any errors it will prompt you or else the R.java file will be created in your gen folder and imported in your project.
If there is any problem with the xml file in android, then R.java won't be generated. Please make sure that you don't have any error in xml file, then clean the project by clicking clean button in "Project" option and click "Build Project", Build Automatically is not selected. This should solve your problem. Best of luck.
You have updated the android sdk but not updated the adt to match with it.
You can update the adt from here
You might need to update the software source for your adt update
Go to eclipse > help > Check for updates.
It should list the latest update of adt. If it is not working try this
go to eclipse > help > Install new software
Click on add
add this url : https://dl-ssl.google.com/android/eclipse/
give it any name.
It will list the updates available- which should ideally be adt 20.xx
Eclipse will restart and hopefully everything should work fine for you.
Try to fix all error in your XML file. Look drawable, layout and other res folders closely for any error.
If it does not fix your problem then try
THIS answer :
Hi can anybody help me with the Eclipse SDK. I have cleaned my Android project then suddenly all of my Java class is in red and I can't build it, all of the references like the
the R has a red mark in it and before I cleaned it, the R was in blue. It always does this when I clean the project and sometimes build it.
setContentView(R.layout.id);
I tried to delete the gen folder then clean it again with the auto build uncheck then build it again then clean it again.
I also tried closing the Eclipse SDK and then opening and cleaning it again but to no avail.
I tried everything with this one can anybody help me? and thanks! Also can anybody recommend a good SDK for making android projects because Eclipse really sucks and thanks again!
If everything was fine before the clean, then the errors may happen because the generated classes (R, that is) has not yet been generated but eclipse already started to validate your classes.
You probably need to refresh after a little bit, or, if you set eclipse to auto-build sources, just wait a bit longer. Repeated 'refresh' (F5) often help also in this case.
As for alternative IDE: You could try android studio or the intellij IDEA community edition.
Hey add this in your imports and check if it works...
import yourPackage.R;
Update :
1) Go to your sdk manager.
2) If there is a build tools update or install then please update or install it.
3) Restart the eclipse..
4) Enjoy.........
When you clean, you'll get errors on everything referencing R as it doesn't exist. It needs to be rebuilt by Eclipse (in the Project meun, there should be an option for "Build Automatically"). Just give it a couple of minutes after cleaning and it should resolve itself.
(You can follow the progress in the bottom right corner of Eclipse "Building workspace...")
delete the imported R file and try again..
The title says most, but I have created a new project in Eclipse. I have everything set up, and as soon as I create a new Android Application Project, once everything has Generated there are 2 Errors: both "R cannot be resolved to a Variable", on Line 19 and Line 12. In the Video Tutorial Series I am watching it says there should be a file called R.java in the gen folder, but there isn't, just an empty folder. The Android project is completely new. Here are some of the things I have tried after googling, none solved the Issue:
Clean Project
Uncheck/Re-Check Build Automatically
Build Project
Close/Open Project
Check XML files for Errors - only the Two Errors as mentioned above in the Error Log
add "import android.R.*"
Create R file manually (Add -> Class)
It is my first time writing an app in eclipse, I know there are a lot of questions like this but none seem to solve my problem. The Java Errors (R not resolved to a variable) Errors are the only errors, no errors in the XML or Anything.
So that you can check my project, I have put it in my Dropbox if you want to have a look at it in eclipse.
Project Download Link
You can create the new Project and then copy the contents of this project into the new one.
This problem is with Eclipse. I recommend you to use Android Studio.
What might help, would be to create a new project and transfer the current project to that one. When the R file is not created when creating a new project, try and re-download the development tools and sdk.
I'm sure that the problem may be with your ADT tools in eclipse. Sometimes, this errors may occur due to some installation mistakes or some sort of software cracking problems. I also faced the same problem at my starting stage. The best thing that you can do is to move on with re-installation of ADT in you eclipse. It may help you. Try this!! Create you new Android Project and Enjoy buddy !!
I was having this exact problem, and found the solution after much headache.
In eclipse, find and click the button labelled Android SDK Manager (next to save, and all that jazz on the toolbar).
In the manager, make sure that under the "Tools" folder all of the relevant "Android SDK Build-tools" have been installed. Once they are, restart eclipse, and your R.java file should be generated. Hope that helps!
I get this error when I try to clean a project:
ERROR: Unable to open class file ....R.java: No such file or directory
So I can't build my projects any more. But R.java is there in the gen folder and looks fine when I open it.
This happens to every one of my projects. I tried completely deleting the Eclipse folder and reinstalling it (Helios on Windows) and Android ADT. No luck.
I have also tried moving my workspace to a different drive. No luck.
I made sure all folders in my workspace are not read only. This worked the first time, but immediately the error came back when I cleaned my project.
This all started right after installing ADT 10.0. I am wondering if it somehow is building R.java as a read-only file.
EDIT: Is deleting the eclipse directory sufficient to reset all of its configuration?
More info: All my projects are fine, until I rebuild or clean them. Then every class that looks at R.java throws an error.
Did you try to remove "bin" and "gen" folders and after that make clean/build?
I have somehow managed to fix it, but I don't know exactly what did it. Here are things I did.
Deleted eclipse directory and reinstalled it and ADT.
Deleted my original project that was the first to have the problem.'
Created a new project with my original's project name.
Manually copied all my class and res files into the new project and refreshed it.
Pasted the text of the old manifest into the new manifest.
I did all this, because simply importing the original project again didn't solve anything.
After the above changes, my other projects still had the problem after pressing clean on them. But then I could fix those by deleting the Gen folder, and making sure the Java Build Path had all folders checked.
I think format C: and reinstalling windows
will be preferred way to solve this issue :)
now for serious that work for me
install all updates restart eclipse and close your project
restart eclipse and delete gen from eclipse and rebuild your project
if you're having the problem for all of your projects, it could be this:
"Debug certificate expired" error in Eclipse Android plugins
that's what fixed it for me, even though I wasn't getting any debug certificate errors. apparently the debug certificate is only valid for one year.
I found this issue reported for Mac:
But it's the same for Windows, and I guess, for Linux. I've posted there a workaround, very similar to the one by TenFour04, but without the need to reinstall anything:
Delete project from Eclipse;
Delete all project generated and configuration files and folders (bin, gen, .classpath, .project, default.properties);
Go to Eclipse and create a new Android Project (do not import an existing one) choosing your original source files;
Adjust all setting (JRE, libraries, linked files, aspects, etc...)
Clean.
Helo guys,
:) This my solution which work for me fine in eclipse.
First : You need to make a copy of the file who make the problem.
Second : delete this file from eclipse
Third : Project >clean
After you can restart your delted file from the location where you have saved it.
Have a nice day
I am getting an error in my Problems tab for my Android Project in Eclipse. The error is "Android Packaging Problem" with an Unknown location.
Unknown Error NullPointerException
I cannot determine what this problem is. My project was working a few hours ago. The only change I made was to add a public interface ITrackDao to my project and implement it. There are no errors associated with this.
I am not even sure where to begin to look. I cannot launch the application. Can someone give me an idea on what area I can look into?
Thanks
Peter
I was confronted with this problem too, and I solve it by clicking Menu->Project->Clean. The error goes away after cleaning the project.
I had a similar error - but instead of a NullPointerException it was an InvalidoperationException from somewhere in Eclipse.
A Project > Clean solved that one too.
Cleaning the project was not enough for me. I had to first remove a <classpathentry/> that specified the interface from the .classpath file and a <linkedResources>'s <link> to the same interface in the .project file before cleaning the project would remove the error.
I had the same problem. I tried the clean up option but for some reason it still did not work. I copied my project and pasted it as a new project and that cleared it up for me.
I had this same error in an imported project and cleaning was not helpful, however by deleting the library references in the .project and .classpath eclipse files, and then relinking things and cleaning, I was able to get things building again.
First I should recommend that you start using subversion or other versioning on your apps, that way you can pinpoint every change between each iteration. If your project was in subversion you could compare with previous and then pinpoint what changed.
With that said, I would also check through any recently changed layout XML, make a change and hit save and make sure you don't get errors. I've experienced strange null pointer/errors in Eclipse at times when my layout was fine, and by making a change and saving, the errors go away.
I ran into the same problem coz of my blackberry sdk installation. I think it messed up my eclipse 3.6.2 install . I just reinstalled eclipse and it all worked like a charm
I worked with a SVN project and one installation have eclipse Galileo. The other have updated to Helios.
In Helios I found this problem and clean is no solution.
After Galileo reinstall (all installations equals now), I deleted workspace and a new checkout resolved the problem.
I had the same problem. I tried the clean up option but for some reason it still did not work. I solved this problem using this step
Project name ->Android tool ->Add support Library