I am a newbie to android programming .I was doing tutorial from Commsware tutorial , to be precise T3 tutorial during which I cleaned the project.After that R class file has stopped generating.
I deleted that project,looks like the same error is getting propagated to other new projects I am creating.
This error is coming for the newly created project also.
I tried all the solutions in stackoverflow like : cleaning project,selecting android version in build path , deleting my workspace,freshly install eclipse etc..
The other intimidating thing is my res folder does not show any errors and my xml file does not contain any capital letters.
It must be some silly error which is causing this?
Perhaps you should take a look at this if you've recently updated SDK tools.
After updating to SDK Tools to rev. 22 for the first time, you may need to relaunch Android SDK Manager again and install a new item: Android SDK Build-tools.
After installing this, clean your projects and rebuild.
this happened to me after updating the android dev kit and esclipse.
couple of things you should try.
if you updated ADT, you must restart ADB server. you probably haven't read the message that says after update. or maybe restart whole pc.
if you're using external jar files, rename the libs folder to lib and revert it back to libs (from eclipse, f2)
There seems to be a problem with the target build settings within your projects.
The R file will not be autogenerated if there is the slightest error in your project. E.g if you use elements in a layout xml file that are available only in Android 2.2 but your project targets android 2.0. Sometimes the offending elements don't show up as errors because, syntax-wise, they are correct.
I advice you look at your target builds in android manifest.
Or target a higher android build (Get the latest one via SDK manager)
Related
This question already has answers here:
"R cannot be resolved to a variable"? [duplicate]
(30 answers)
Closed 9 years ago.
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 > 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.
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.
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.
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.
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.
In addition to install the build tools and restart the update manager I also had to restart Eclipse to make this work.
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.
I have tried so far every solution; clean, change the namespace etc. I still cannot get this resolved.
I have created an Android project with API 19 and it creates another project alongside mine called appcompat_7. This project has quite a few erros and one of them is " article_view cannot be resolved or is not a field ".
The following files have the errors;
ArticleFragment.java
HeadlinesFragment.java
MainActivity.java
All of these files seem to have issues with R.layout.*
I am not sure what would resolve this issue at this point as this is completely new project and I have tried almost every API above 17 and each project has definitely an error that does not get resolved with clean etc. I am using Eclipse Luna and I am sure I was able to install the correct SDK.
As a note: Am I the only one who thinks this IDE for Android is somewhat messy and not friendly at all?
Thank you for any insight.
Edit:
I solved the problem by trying API 18 for both compiler and target. It did not create the appcompat_v7 project so I just fixed the dependencies and changed the namespaces. I still think Eclipse is not working well with Android plugin.
I was also stuck with the same issue few day ago,
I resolved the same issue by updating sdk to latest version 23.0.4. and extras: Android support Repository to rev. 6 Android support Library to rev. 20
first of all open up your Android sdk Manager from eclipse and download all latest sdk updates and extra downloads.
And then after downloading all updates , you have need to use a fresh Eclips editor because your existing eclipse will not let you successfully update from Android sdk tool 20 to 21.0.4 Then just use a fresh eclips editor and set up updated android sdk path in the fresh eclips (the same one you have used in your last eclipse editor , you can find it at Window>> Prefrences >> Android).
Hopefully this will solve your problem.
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!
Every time I open Eclipse, I get the following error messages:
Android SDK Content Loader:
parseSdkContent failed java.lang.NullPointerException
Initializing Java Tooling
An internal error occured during: "Initializing Java Tooling". java.lang.NullPointerException
Loading data for Android 2.2
Parsing Data for android-8 failed java.lang.NullPointerException
Loading data for Android 2.3.3
Parsing Data for android-10 failed java.lang.NullPointerException
Loading data for Google APIs (Google Inc.)
Parsing Data for Google Inc.: Google APIs:8 failed java.lang.NullPointerException
See link for screenshot:
http://i.stack.imgur.com/lhhQQ.png
(I am using OS X Lion, and Eclipse Helios)
First i read some posts saying that it was the AVD.ini file in the .android profile that was causing the trouble. I tried deleting all the entire .android profile folder as suggested in Android SDK Content Loader failing with NullPointerException. This didn't correct my problem.
I tried deleting the entire Android SDK folder, downloaded it again and installed a couple of Android versions through it. Still the same error messages...
To ensure that I didn't have any old plugins or something that were the issue, I uninstalled eclipse, downloaded it again and installed the Android plugin again. (So the plugin is up to date).
When I go into one of my Android projects, I get error messages on places where I acces resources by using the R file. Regular Java projects work fine, but all Android projects gets small red boxes with white crosses on them. I have been searching for a solution to this problem since yesterday, but at this point I'm completely qlueless and would appreciate any help I can get!
Close all open projects and exit Eclipse. Now you can open Eclipse without getting the error. Start opening your projects one by one to find which one causes the problem. This is most likely because you deleted a Device profile inside the AVD manager.
Do not delete all the full .metadata
Backup .metadata
delete only .metadata/.plugins/org.eclipse.core.resources/.project
restart eclipse
Observation : the projects folders are created
Further - if you are using svn/git/hg have code repository links it would be destroyed, so to reinstate
close eclipse
copy relevant projects from backup to merge with current projects in .metadata/.plugins/org.eclipse.core.resources/.project
restart eclipse
Downfall - sporadic fail error may occur (sync or something) - harmless
backagain
I encountered exactly the same issue this morning. This is a workspace related issue.
Solution 1
I looked into my .metadata and read .bak_number.log files . Some layouts failed to parse and my projects were out of sync with the file system.
So I deleted all the .bak_number.log files. Relaunch Eclipse and the whole worskspace should work again the way you left previously.
Solution 2
However if it's not due to out of sync with the file system. Change the workspace then import all the eclipse projects from the previous workspace.
Thanks the project.properties files , the dependencies are still kept.
PS : I should return to IntelliJ :)
first close your Eclipse
Go to your workspace and rename .metadata to tushmetadata and go to
tushmetadata- >.plugins -> org.eclipse.core.runtime -> .settings
and copy all files from it.
now open the Eclipse and go to your workspace there you can see the
newly generated .metadata folder in that go to .plugins ->
org.eclipse.core.runtime -> .settings and paste here and do not
overwrite any file.
Try to "Hello World" project and run it.
Try to delete file .metadata from your android workspace folder. .Metadata folder contains all configuration files for eclipse. It works for me.
Your answers might be right. What I did was to change my workspace. I redownloaded the project I was going to work on from git, and reimported it. Now it works fine :) Maybe there was some files in this project that made the error messages apear? Dunno....
I have remove the .metadata folder but after it, when I run the eclipse, I cannot creates any Android project. To solve it, I have done the follow:
Go to the main work directory of eclipse
Localize the folder com.android.ide.eclipse.adt It should be in .oldMetadata/.plugins/
Copy it to the new eclipse configuration: .metadata/plugins/
See the full solution here:
http://www.jiahaoliuliu.com/2011/06/running-android-sdk-in-eclipse-errors.html#solution4
For me, the source of the NullPointerException problem was a host-side Junit test project that references (and tests) code from an Android project. It didn't have a project.properties file. It's not an Android project, but for some reason the newer versions of the SDK somehow expects the file there. To fix the problem, I just copied a project.properties file from an Android project to the host unit test project.
When I met this problem about a year ago, I had some projects in my workspace that needed a specific Android SDK level (let's say 2.1) and i didn't have it installed in the Android SDK.
slott's answer helped a lot. Deleting the .metadata or reinstalling eclipse didn't though. The trick was to isolate the project causing the problem, delete its .settings folder and .project file and reimport it.
I discovered another cause, where I'd added a space character into an otherwise blank line in the project.properties file. When I eventually ran android update project -p .
the program (android.exe) threw a NPE exception. When I deleted the space from the blank line the android update project command worked and eclipse started behaving (after running clean a few times).
This happened with r20 of the Android SDK on a Windows 7 64-bit machine.
FYI my change that fixed the problem in project.properties is public at http://code.google.com/p/android-daisy-epub-reader/source/detail?r=517
This is just weired.
In my case when I took a subversion update, I was getting this problem. The reason was the corruption of my project.properties file (due to subversion conflict).
I just corrected the file and problem got solved.
I found it's just missing project.properties file in the project folder. After copying one from another project the error is gone. The only valid line in project.properties is
target=android-8
If you are using SVN or GIT please check whether the project.properties has conflicts or not.
Sometimes project can not be open because of this.
I hope this is useful to someone and saves his/her time: My colleague was facing same issue and we did almost everything mentioned here, with no luck. In the end we changed the Android SDK version in the manifest file and it worked.
This solution worked for me.
Close Eclipse and delete all .markers inside your workspace folder.
Restart Eclipse (once I had to restart it twice, it hang on the first but worked on the second for no aparent reason).
Of course, it's always safe to back them up first.
I am a very beginner in android development using eclipse..
I have given an assignment to modify the android application made by a professor..
so I downloaded the file and imported it to eclipse.
My professor can normally run the program..
however, when I tried to test it before modication using simulator, " the application is forced to stop unexpectedly" is shown..
Moreover, I found that all .java file in src contained "x" ...and the codes in the .java file, like "import android.graphics" or "private class xxx" all contained error..which i have been told that "import andorid.graphics" cannot be resolved..
Could anyone tell me what's wrong with the codes...
and kindly provide me the procedures to fix this problem?
is it possible for me to send the zip file to someone..so that he/she can help me find out the problem??
Make sure the Android sdk and ADT are configured properly in Eclipse and you have updated the relevant packages using SDK Manager. Best way to test this is to create a HelloWorld Android app
http://developer.android.com/sdk/installing.html
Assuming that you have correctly installed the same Android SDK that your professor is using, the first thing to try is to right click on the project name, then select Android > Fix Project Properties.
I've often found that importing existing Android projects into a workspace can be problematic, especially when the project comes from a different machine. A work-around is to create a new Android project, then copy all the sources and resource files into the new project. It's a pain, but it avoids many problems that arise due to different development configurations.