R cannot be resolved to a variable - android

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.

Related

Unable to re-generate R.java in android project

I am working on one android application. Don't know why but i am not able to regenerate R.java file.
i also searched a lot about it. and also tried all the solutions i got from various place. but R.java is not generated.
if i import my project in another computer, then it is working fine. only have problem in my eclipse. :(
i also solved all the lint errors, warnings and also tried to clean and build project. i also checked my all .xml files as well as all images. all is perfect not any special symbols or uppercase. and and tried all the tricks which i got. but now able to generate R.java file.
please help me.. Thank in advance...
Edit :
right now i am getting one error like
Description Resource Path Location Type Error executing aapt: Cannot
run program "..\Android_SDK\build-tools\18.0.1\aapt.exe":
CreateProcess error=5, Access is denied: CreateProcess error=5, Access
is denied TestProject line 1 Android ADT Problem
Occassionally I am also fighting with this issue. Sometimes it's tough, but it's usually that something is wrong with your /res/ files. Usually XMLs.
First try to Clean your build, but you did that already.
Look for malformed XMLs, they do not have to be marked in red at first, but try to open them all if you don't see them popup in red. Check that you don't reference ids to another views in styles.xml, check for invalid characters in keys, check for invalid/unescaped characters in content of xml entities.
Also check properties of your project and make sure that all Java Build Path components are checked (Order and Export). Mainly Android one. Sometimes it happens to me, that it's unchecked making my project unbuildable.
If it works on another computer, it seems the code is fine. The problem seems to be either your toolchain or your Eclipse workspace.
Try the following:
If you use Android SDK Tools 17 or higher, make sure you install the corresponding Android SDK Build-tools in Android SDK Manager.
If the above doesn't help, create a new workspace and import your existing code into it.
This is common problem, which can be caused by many different situations.
What always worked for me:
If your R.java is not generated, your project is flooded with errors saying that class R is not recognized (obviously). Usually, somewhere between all those R.java errors, there was one other error (with different that all others) which is often overlooked because of hundredths R.java related errors. If i fixed this other error, R.java is generated after clean/build...
Edit: the "other error" i am talking about that is preventing your R.java to regenerate, is often found somewhere inside resource XML files...
The problem is in your installation path of Eclipse. Just check that your path doesn't have any spaces where you have installed Eclipse. And name should be proper for the Eclipse directory.
I also had the same problem because my Eclipse installation path got spaces in it, and my Eclipse directory name got changed to some symbolic name. When i renamed it to Eclipse and make the installation which contains no space, it got worked.
For example if Eclipse directory path is like
D:/New Folder/Android/Eclipse
Then it may got problem because of space between "New Folder".
Check your path and directory name and if it worked then check my answer please.
I was struggling with this issue for past one hour. I just solve it by
Remove the ".metadata" file from the workplace directory.
Then start the Eclipse.
Import the project from the workplace by File -> Import -> Existing project into workplace under General tab.
The R.java file will be generated. You need to import all other project that were in your workplace the same way.
Hope this will help someone

no R.java in gen folder - android

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.

Eclipse error : Your project contains error(s),please fix them

I am using Eclipse Classic 3.7.2 working only on Android. I use Ubuntu as my OS. When I run any basic Android application on Eclipse say "Hello World", it results an error called Your Project contains error(s), please fix them before running your application.
Now I have googled and checked here and may others but I did not get the solution.
I also tried Project > clean... but it isn't working.
Windows->Show Views->Problems shows 2 errors:
Error generating final archive: java.io.FileNotFoundException:/home/android/Desktop/helloworld/bin/resources.ap_does not exist.
Unable to parse aapt...
It may be be because of Eclipse's debug certificate expiration.
Please look at to my this answer.
Close and restart Eclipse. It works everytime !
Its bug with deleting android projects I think.
I have faced exactly same type of issue. Just update your eclipse ADT plugin to latest version.
After update clean build the project.
Go to your .android folder and delete your debug certificate. In my computer it is in this path
E:\Users\(ur profyle)\.android
Inside that there is a file name 'debug.keystore'. Delete that,clean and try to build the project again. Sometimes this error is caused when the certificate expires.
You need to update your Eclipse to the latest available version(Indigo) and then need to update the ADT(level 16 I think), as the latest ADT updates works on Indigo only. After the updates close and reopen the Eclipse, it should work now.
Go to Project Properties -> Java Build Path
Select Libraries and remove Android Dependencies
After this my problem solved.
The error was because of updating
Set your Android sdk path once again and restart Eclipse. It fixes the issue (window-preferences-android-sdklocation).
Or, just update your Android tools and restart Eclipse works.
Check your libs folder ..
some libraries cause this ,
it happened to me once and i was use Apache POI .. i tried to delete the jars from libs folder and it's worked ..
I had this problem in Eclipse after executing Project => Clean... That option deletes all the compiled stuff from your project and, therefore, the java classes start looking like if they all have errros.
To fix that problem I had to:
1. open my java clases and XML layout files(for android dev)
2. do a small change, something like a adding a space
3. Hitting Crt+S to ask eclipse to save and compile the class once again.
This solution may or may not work for you. I recommend looking at your specific problems using the Problems tab of Eclipse (Found at Windows=>Show View=>Problems) since it tells you about the exact errors and other very useful information.
If you're using android support library make sure you have not added jar files ( android-support-v4.jar and android-support-v7-appcompat.jar ) in your libs folder.
you only need to add android-support-v7-appcompat as library on your project.
It worked for me the time I had the same issue
My project had no errors in it but I noticed another open (unrelated) project which did have errors. I closed that project and my other project worked fine again.
Now the "unrelated" project used to be related but I'd removed the dependency ages ago. Closing it solved my problem so I have to assume there is some Eclipse bug in there somewhere which is still linking to it in some way. I'd say if I created a new project and copied everything in it might have achieved the same result.
As a test for yourself.. maybe close all other projects except the one you are working on.

"R cannot be resolved to a variable"? [duplicate]

This question already has answers here:
Developing for Android in Eclipse: R.java not regenerating
(64 answers)
Closed 9 years ago.
In Eclipse, I've created a project from a source and now it shows errors - "R cannot be resolved to a variable". From what I found here, I had cleared and rebuilt the project, but still the R file doesn't appear in the /gen folder.
Any ideas?
Dont worry. First you may clean the project, then run the project. If this does not work then follow the following links:
Here is the best way to solve this problem: [Android Development- Where is my R.Java file?][2]
R.java not regenerating
R cannot be resolved - Android error
R cannot be resolved to a variable
R cannot be resolved to a variable -- mailing list entry
Fixed: R cannot be resolved to a variable
If Clean/Rebuild Project doesn't work try to check our package name in AndroidManifest.xml.
The problem "R cannot be resolved" happens when you change your package name in the AndroidManifest.xml file. It uses your Android package name to create a subdirectory under the "gen" directory where it stores the R.java file.
For me the error got fixed by making some changes in Android SDK Manager.
Whatever be the latest API level available, install its "SDK Platform". For me latest API level available was 16, so I installed its's SDK Platform as shown in the image below. It works fine now.
Cheers, Mayank
Did you just update both sdk and adt(from 21 to 22), then you need to install a new item: Android SDK Build-tools
Refer to:
Eclipse giving error, missing R.java file after recent update
For me somehow the Project properties; Android; Project Build Target was not set. I chose a Android version there (e.g. 4.2) and it fixed it.
for me, the best solution to suggest to people that have problems with the "R" file would be to try the next steps (order doesn't matter) :
update ADT & SDK , Eclipse and Java.
remove gen folder , and create it again .
do a clean-project.
right click the project and choose android-tools -> fix-project-properties .
right click the project and choose properties -> java-build-path -> order-and-export. make sure the order is :
Android 4.3 (always the latest version)
Android private libraries
android dependencies
your library project/s if needed
yourAppProject/gen
yourAppProject/src
make sure all files in the res folder's subfolders have names that are ok : only lowercase letters, digits and underscore ("_") .
always make sure the targetSdk is pointed to the latest API (currently 18) , and set it in the project.properties file
For me, there was a missing slash at the end of my SDK. In Eclipse > Preferences > Android > SDK Location
For example, change
/home/matt/android-sdk-linux
to
/home/matt/android-sdk-linux/
your android manifest must start with correct package
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="HERE - Correct package NAME"
android:versionCode="1"
android:versionName="1.0" >`
I got similar problem and solution I found out was in resources any of
the file aka background, sound etc must not contain capital letters or
any special symbol other than _
What you really need to do it just install "build-tools" from sdk manager,
and r.java will be generated automatically.
I had the same error. Error was that, I had placed a file in res/raw folder with invalid filename.
As soon as I corrected the file name to a valid one, error was resolved!
Allowed characters for naming a file:-
1. a-z
2. . _
3. 0-9
4. no capital letters
Capital letters were the issue in my case!
Sometimes you can accidentially add an import to "R", so if at the top of your code you see some weird import about that that you did not add yourself, delete the reference, and everything should go back to normal
My problem was strange and took some time to find. Somehow the package of the src file changed so that the last entry in the package was deleted. So for example initially my class MyActivity.java was in package com.abc.client.test.app but after I added a user permission, the app got removed and the package was renamed to com.abc.client.test. I don't know how it happened. Renaming the package and putting the java file in the correct place fixed the problem.
I found this problem when trying to run the Notepadv3 programme from Googles 'first lesson'..
For me it was an issue with the xml file, due to the API level I was using. I renamed each case of Match_Parent to the older type of Fill_Parent. Oh and if you have already auto-built the project then you need to delete 'import android.R' on NoteEdit.java and Notepadv3.java, clean the project (click 'Project', then 'clean...') before saving.
Solved it for me. Came from this post Android NDK r4 san-angeles problem
Can't believe Google dosen't warn of this problem - I have been setting up another PC to start programming again and even with a bit of prior knowledge this was a pain.. How do you set the API when importing an existing project??? Can't see where there is any dialogue option when you 'File' 'Import' etc ..
Scamparelli
Check the androidmanifest.xml file and layoutfolder xml files. They should be created properly as the starting and ending clause in xml should be placed properly. Update the files, clean and build. And all set!
I had this problem and none of the other guides helped, and then I realized I didn't have the java jdk installed on my system. If you haven't done this either go download the version corresponding to the version of eclipse you installed (x86 or x64)
It is possible you have an error in your *.xml files: layouts and etc.
Try to modify AndroidManifest file.
For example add space and delete this space. After this OPERATION, save project. Resources will be refreshed. It can help.
I solved the problem with resolving R resource on fc19.x86_64 and ADT v22.0.5-757759 by installing additional libraries after Fedora and ADT upgrade.
yum install ld-linux.so.2
yum install libstdc++.so.6
yum install libz.so.1
Those libraries are required by adb (Android Debug Bridge version 1.0.31).
Then restart Eclipse and perform project clean Project->Clean check project you would like to clean.
Hope it helps :)
Project > Clean...
usually regenerates R.java file located in gen/com.mypackage
In my case, R.java wasn't getting generated because of a hierarchical parent error, which in turn was cured by updated one or more Eclipse plugins (Go Eclipse-->Help-->Check for Updates)
I got this error when I added a js file to the res folder.
An error indicator was set on the res folder icon. In all the classes where I used R I got this error.
I moved the js file to the assets folder and everything worked.
Problem was eclipse was not generating R.java.
To resolve this issue please go to project->clean... and select your project and select ok and then clean and build project and import your package name R file(Ex com.demo.R). It works.
This can happen when the android naming convention isn't followed. Check if you have placed a file/photo into one of the android folders and make sure that the file name contains only lower case letters
I know this is an old question but I just solved my own version of it and perhaps this might help someone.
After two days of tearing my hair out with this, I finally got around it by deleting the raw folder, then recreating it and dropping the file(s) back in.
After that, another Project > Clean and it at last compiled.
I got this when I renamed a project. Although the project is renamed, some references are not. Clearing lint, and then rerunning lint helped. (Right click project > Android Tools > Clear Lint Markers, then Run Lint)
My setup was broken after a recent update where the SDK build tools need to be installed separately after the SDK installation. So build tools update + Eclipse restart fixed this for me.
Credit goes to the Android reply here
When other solutions fail, select your project and delete it. MAKE SURE YOU DO NOT REMOVE FILES FROM DISK.
Then use file>import>existing android code into workspace, and select the location of your project.
I been having this and i did trace it back to the layout files.. It happend to me again however i could not find noting in the layout files. I looked in the string.xml and there was it.. one of the string names started with cap and that was causing the problem.
Fix any XML formatting errors in the XML Files in your /res/menu folder.
Might be a compile time error from the XML file being improperly formatted.

Your project contains error(s), please fix it before running it

I am developing a simple Android application. But when I run Eclipse, it shows the following error:
Your project contains error(s), please fix it before running it.
I can't find any error in my project or there is no error in my application.
There is a red cross under the application name but it is not under another file name.
Does anyone else have this issue?
That usually comes from errors in the build path.
If you're using eclipse, there is a view you can add that lists all the errors called "Problems":
Otherwise, you can try to clean the project, and that usually solves a few problems.
Finally, if you add or alter resources from outside your IDE, you'll want to reload the resources and clean.
EDIT (Comment by anonymous user)
This can also be caused by an out of date "Debug Certificate" fixed as follows:
IF ALL FAILS THEN THIS GOTTA BE THE SOLUTION:
Delete your debug certificate under ~/.android/debug.keystore (on Linux and Mac OS X); the directory is something like %USERPROFILE%/.androidon Windows.
The Eclipse plugin should then generate a new certificate when you next try to build a debug package. You may need to clean and then build to generate the certificate.
This is also another fix for the "setContentView(R.layout.main);" error that says it cannot find R.layout.main when it is actually generated. (R cannot be resolved to a variable).
This is also another fix for the error "Your project has errors..." and you cannot find any.
Clean and rebuild are still necessary after generating a new debug certificate.
First go to Window -> Show View -> Error Logs in menu. It will display error logs if you have any. Then try to clean the project and build it again.
Well, in my case some libraries were addressed twice in the:
Project >> Properties >> Java Build Path >> Libraries
I just had to remove the duplicate and it worked fine without any cleanings or refreshing.
I saw this with an existing project. I had made a few edits, but hadn't imported anything new. Restarting Eclipse didn't help.
Project->Clean did solve the problem.
I come across this error often when I import a new project in my workspace.
Reason: Some necessary files (Like R.Java) is not generated in its respective packages.
Cure: Clean and build projects, All the files that needs to be auto generated will be there on place after building the project.
Best Luck.
This is happened to me. After format of my system,
When i import project it shows same error
remove first debug.keystore file then goto -
Project -> Project properties -> select library -> remove -> add again libraries.
It's working for me......
Go to projects menu, click on clean menu item.
After that close the eclipse and reopen and try compiling..
It is software glitch you find some times.
it can also happen if you move required files. Simply check Problems View (menu window -> show view -> Problems) as told here
I had this exact same problem. One solution that would work would be to create a brand new project, but I don't think there's any need for that. For me the problem was that the debug certificate that gets auto-generated had expired. Deleting this file allowed Eclipse to rebuild that file, which solved the problem. You can't run an app with an invalid certificate, whether it be a debug or release certificate. Note that cleaning my project did not work. For more information, see:
"Debug certificate expired" error in Eclipse Android plugins
Recently I came across this error. I was really in a corner with no help, then I figured it out. This error can occur for the following reasons:
An error in the project code
Improper linking of external library files to the project
Most important: if your debug.keystore file is expired.
The first 2 cases are easily identifiable but the third one is like searching a black box in a dark room.
So in addition to Project -> Clean, remove your debug.keystore file also.
I am using Mac + Eclipse so to remove, I wrote the command rm ~/.android/.debug.keystore in a terminal.
Is there a way to ignore existing errors in project. Something similar what eclipse allows in case of java projects.
In my case the errors exist in jni directory. The errors are shown even though ndk-buid succeeds. So all i want to do is to ignore the errors reported by eclipse.
If the errors are indeed errors then i should get unresolved symbols during ndk-build.
I have ensured standard android includes are there in include path.
Also my project is of type android/c/c++.
I have two builders associated with the project
1. statndard android builder
2. custom ndk builder that ive explicitly created.
Simulate your self some error in class. Then save it and it would show more errors than you simulated. For me it was incorrect import and this helped.
I have had a similar problem.
Under "problems" tab I have found an error saying "Error generating final archive: Debug Certificate expired on 2/22/12 1:49 PM"
So my advice is to look in the problems tab to get some more info.
Bye
If none of the above solution work, you should check the READ ONLY property of the Project folder, if it is Read-Only, the compiler will not be able to overwrite the resources, R.java and other dex APK etc files and hence this will occur..
This happened to me and I fixed after a long struggle..
Happy Programming.
For some reason eclipse only showed a ! error on root and didn't specified what error it was.
Go in Windows -> Show Views -> Problems. You might find all previous errors there, delete them, do a clean build and build again. You'll see the exact errors.
Eclipse shows an error on android project but can find the error
I had this exact problem when trying to run the Doodlz app, from the book Android for Programmers, on Mac OS X with Eclipse Juno.
After downloading and unzipping the demos from the book, I forgot to change the permission of the files. They were read-only on my system so this was the first issue.
The second issue was solved by selecting a build target on Eclipse. This was fixed by going to: Project > Properties , and clicking the Android field on the left panel to be able to select one option as the Project Build Target, which in my case was:
Target Name Vendor Platform API Level
> Google APIs Google Inc. 4.0.3 15
Then cleaning and rebuilding the project showed no errors.
Finally, to run the app right-click the package (at the Package Explorer tab) and then select:
Run As > Android Application
Simply Deleted my debug certificate under ~/.android/debug.keystore and Project->Clean did solve the problem.
Delete the .android folder from your Documents&settings\User\ on XP and \User\ on Win7. Recreate the AVD again and create a new project.
What caused this problem for me was none of the above, but simply that I'd left the "debuggable" attribute to false in the manifest.xml file after doing a release. D'oh!
Of course neither the LogCat, Error log, Console, or Problems window alerted me to this..
I had the same error, when I copied a project to another computer.
I then checked all properties of the project on both machines, and the only thing that was different was the order of items in Java Build Path - tab Order and Export.
I moved the items Android X.X.X and Android Dependencies above the other 2 in the list (in my case, src and gen folders) and voila, it worked again!
I'm not really sure if the different order was actually the problem, but at least changing it (and saving the properties again) seemed to help...
I had the exact same problem after updating the SDK and ADT.
My issue was resolved by deleting the .android folder (hidden) under C:\Users\USERNAME\
This happened to me when I was experimenting with Maven.
Right click project -> Maven -> disable maven nature
corrected the problem for me.
Yes, this is a rather cryptic message. If you've got a faulty project (say one you've been working on in the past) then you'll get this message (and no messages in your current project's Problems / Error Log panes).
You may just want to run your current project. This may be perfectly fine. Just click on the down arrow to the right of the Run button to select your project.
Try changing your workspace. I am not sure this is the exact solution . I did face the same issue for sometime untill i changed my workspace.
In my case, it happens with ADT 22.
I choose not to create Activity.
After I remove the "appcompat_v7" as library project. I works.
I had similar problem where I couldn't run my project yet didn't see any problems in the code. In Error Log panel it said something like "Cannot add P/ to the list of segments P/ in as a parent".
Restarting Eclipse solved the problem.

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