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.
Related
I just downloaded and installed the new Android SDK. I wanted to create a simple application to test drive it.
The wizard created this code:
package eu.mauriziopz.gps;
import android.app.Activity;
import android.os.Bundle;
public class ggps extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
but Eclipse gives me the error
R cannot be resolved
on line
setContentView(R.layout.main);
Why?
PS: I do have an XML file named main.xml under res/layout/.
After tracking down this problem as well, I found this note in the Android documentation:
http://source.android.com/source/using-eclipse.html
*Note: Eclipse sometimes likes to add an "import android.R" statement at the
top of your files that use resources,
especially when you ask Eclipse to
sort or otherwise manage imports. This
will cause your make to break. Look
out for these erroneous import
statements and delete them.*
While going through the Android sample tutorials, I would often use the Ctrl + Shift + O command to "Organize Imports" and generate any missing import statements. Sometimes this would generate the incorrect import statement which would hide the R.java class that is automatically generated when you build.
Each time I had a problem with R not been generated, or even disappeared, this was due to some problem in the XML layout file that prevented the application from being built.
Whenever you get
R cannot be resolved
then check for the /res directory and there must be some file that have some error in it and that is preventing the application from being built. For example, it may be a layout file or it may be due to some missing resource is, but you already defined it in the XML file.
If you have any additional, even unused (!) or unreferenced (!) images in a folder like res/drawables-mdpi which do not comply to the file naming conventions (may contain only [a-z0-9_.]), the R.java class might not generate, causing the chain of events all the other posts referred to.
my project have include a r.java.at the beginning ,R.layout.main work good.But,after adding some code it doesn't work,and the error is R.layout.main can't resolved.what's the problem?
Look at your imports. Chances are that the line:
import android.R;
will be there. If that's the case, remove it, so that your project will resolve R not with the default Android Resources class, but with the one auto-generated from your /res/ folder.
And another thing which may cause this problem:
I installed the new ADT (v. 22). It stopped creating gen folder which includes R.java. The solution was to also install new Android SDK Build Tools from Android SDK Manager.
Solution found here
What Will said was right
R is an automatically generated class that holds the constants used to identify your >resources. If you don't have an R.java file (it would be gen/eu.mauriziopz.gps/R.java in >Eclipse with the 1.5 SDK) I would recommend closing and reopening your project or going to >Project > Build all (and selecting "Build Automatically" while there as recommended by >Josef). If that doesn't work than try making a new project, if the problem is recreated than >post here again and we'll go into more detail.
but I've found out that there was another problem that was causing the first one. The tools in the SDK directory didn't have the permissions to be executed, so it was like the didn't exist for Eclipse, thus it didn't build the R.java file.
So modifying the permission and selecting "Build Automatically" solved the problem.
R.java is a file that the Android Eclipse plugins creates while
building your application. R.java is created under the "gen"
directory. This file is generated from the information in the "res"
directory. If you run select "Project" -> "Clean..." on the Eclipse
menu, it will remove and then regenerate the R.java file.
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.
Eclipse may have problems executing clean, because it is confused about
where the R.java file is when you have changed the Android package
name. You can either rename the subdirectory under gen to match your
new package name, or you can change your package name back to the old
name. Do the clean and then change the package name to the new name
you want. This works best if you stop Eclipse from trying to build
while you are changing the package name. Under the "Project" menu
uncheck the option to "Build Automatically" and also when the
"Clean..." dialog asks if it should "Start a build immediately"
uncheck the box so it doesn't try to build while you are changing the
package name. After you have changed the name you can turn "Build
Automatically" back on again.
Note that if your AndroidManifest.xml file package name does not match
your Java package name, Eclipse will end up automatically adding an
"import <your Android package name>.R;" line in all your .java files
that have any references to R. If you change your AndroidManifest.xml
package name, sometimes Eclipse does not update all of these added
imports. If that happens, use the Eclipse refactoring (ALT +
Shift + R) to change the import statement in one of your Java files to
your new AndroidManifest.xml package name. It is best to do this
while you have disabled "Build Automatically".
R is an automatically generated class that holds the constants used to identify your resources. If you don't have an R.java file (it would be gen/eu.mauriziopz.gps/R.java in Eclipse with the 1.5 SDK) I would recommend closing and reopening your project or going to Project > Build all (and selecting "Build Automatically" while there as recommended by Josef). If that doesn't work than try making a new project, if the problem is recreated than post here again and we'll go into more detail.
Close all files, clean project, restart Eclipse.
It is worth checking in AndroidManifest.xml. The attribute package has the correct value.
That is:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="your.correct.package.name"
...
After you change that, the R.java will be re-generated.
This error can also be caused by adding an activity to a namespace that is different to the root namespace for your package.
For example, if com.example.myapp is the root namespace for your package, you can then add an activity to the com.example.myapp.activities namespace.
This will produce the "R cannot be resolved" error.
To fix the import the R in the default namespace in your activity should be:
import com.example.myapp.R;
Along with the great suggestions in the previous answers, make sure your Android target is set:
Right-click on your project
Choose Properties
Choose Android in the left menu
Tick a box next to the appropriate Project Build Target.
Click Apply and OK
Edit: A year later I found another cause. I had a .jpg image in my drawable folder with the same name as a .png image. Referencing this image in my code must have confused the program and it gave the "R cannot be resolved" error.
Make sure you installed the Android build tool form sdk manager
project right click properties-> Java BuildPath select Library and add android-support.jar the follow these step.
Go to Project->Properties->Java Build Path than select Order and export tab. Set android-support .jar library checked and up it into top of the list. And clean and rebuild..It works for most of the cases
I just had this problem for the millionth time and realized what was causing it: I created an XML file with uppercase letters in the name. All your XML filenames in /res must match [a-z0-9\\._].
Simplest solution - Sometimes you just need to save the XML file you were working on to get the autogenerator to kick in.
Save the file (e.g. main.xml) then delete the R.java file and see if the regenerated R.java resolves the R resolve problem.
Check the XML file names. Be sure that they're all in lowercase.
Also make sure that any image resource names are also all in LOWER CASE. I had a capital letter in the name of my jpg file, and it caused the R unresolved error right across my project.
R is a generated class. If you are using the Android Development Tools (ADT) it is generated whenever the project is built. You may have 'Build Automatically' turned off.
This error cropped up on my x64 Linux Mint installation. It turned out that the result was a failure in the ADB binary, because the ia32-libs package was not installed. Simply running apt-get install ia32-libs and relaunching Eclipse fixed the error.
If your x64 distro does not have ia32-libs, you'll have to go Multiarch.
Check #4 and #5 on this post:
http://crunchbang.org/forums/viewtopic.php?pid=277883#p277883
Hope this helps someone.
You may need to update/install SDK tools. Relaunch Android SDK Manager again and install a new item: Android SDK Build-tools.one by one delete,fix which one work for you.
I had this problem as well. It turned out that I had inadvertently deleted the "app_name" string resource from the strings.xml file, which was causing a silent error. Once I added it back, the R class was generated successfully and everything was back up and running.
You may need to update SDK tools. Relaunch Android SDK Manager again and install a new item: Android SDK Build-tools.
Try to make your new XML layout file name lower case. For example, use my_file.xml instead of myFile.xml.
Yet another reason R.java might not get autogenerated is if you have directories like res/drawable-hdpi, res/drawable-mdpi, or res/drawable-ldpi.
1.6+ seems to be OK with these directories, but 1.5 doesn't want them. When I removed those directories, R.java started autogenerating for me again.
Often times this is because of the MinSDK version number you supplied when creating the project. Example:
If you want 2.1 to be the minimum, Android 2.1 is actually API Level 7.
You can see what I am talking about when you browse the SDK you downloaded and installed. Navigate to the place you installed the SDK to (C:\android-sdk-windows for example) and open the folder named "platforms". You will see something like "android-7" listed as a folder, and if you open that there is a source.properties file that, when opened with a text editor, will show you the corresponding platform version.
When you create a project, and you must select a "Build Target" API, the last column in that list named "API Level" shows the number you are looking for when populating the MinSDK setting.
This is probably one of the most common mistakes that results in the R.java file not being created under Project > gen > packagename > R.java.
Remove main.out.xml. I'm new to this and don't yet know what this file is used for, but removing it cleared the problem.
Just go to Android Top menu list. click on Build Menu, in under Build click on Rebuild Project.
First check is there any error in any xml layout or not, if then resolve it first.
Otherwise remove junit dependency from project and rebuild the project.
In case anyone is interested (I might be saving your life here), I had the error, R.xml cannot be resolved, slightly different on a GLS project. Hmmmm. After looking in R.java, I found an auto-generated class, XML.java, (I think) was not there.
Solution? It needed a new folder in res: res\xml and a file called default_values.xml
in there. Then all was OK.
Just in case you have not got that file, it's:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
</PreferenceScreen>
So I have run into this problem multiple times when switching build targets. Usually doing a Project >> Clean worked for me. This last time, however, it did not. Finally I tried to open my default.properties file, located under the root project folder. I received an error message stating that it was out of sync with the file system. I actually deleted it and copied a coworkers version which allowed eclipse to rebuild my R file. I will paste what it looks like below. It is named 'default.properties'.
# This file is automatically generated by Android Tools.
# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
#
# This file must be checked in Version Control Systems.
#
# To customize properties used by the Ant build system use,
# "build.properties", and override values to adapt the script to your
# project structure.
# Indicates whether an apk should be generated for each density.
split.density=false
# Project target.
target=android-3
I had the examples of Android 8 and was trying to use Android 7 SDK. When I closed the project and reopened the application folder and chose to use Android 8 SDK, it was able to find the R file. Hope this helps.
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.
Compile Error:
Error generating final archive: java.io.FileNotFoundException: ..\bin\resources.ap_ does not exist.
Compile other simple sample works.
Same source file and project works on my college's machine.
Any tips ? Why resources.ap_ doesn't get generated ?
Did you do a Project > Clean? If that doesn't work, try forcing Eclipse to build the project again. Restart Eclipse if that still doesn't work.
I created an empty text file under C:\Users\me\workspace\project\bin\resources.ap_
Then Cleaned/Rebuild... that seemed to fix it.
In my case was a 9 patch drawable that was modified with GIMP, then adb cannot "parse" it, recreated with the draw9patch then worked fine
I was getting both the error in this thread and the one in this post: Android Unknown Command 'crunch'.
Updating the Android SDK inside Eclipse fixed both errors for me.
If you delete the whole "gen" folder, then go to Project>Build All it seems to regenerate the folder and the R.java file
Finally i found the reason. The update aapt tool treat the format string without order as build error. e.g. "%s %d" should be "%1$s %2$d".
I got this along with an error when the "aapt.exe" update tool was run.
There's apparently a bug in this program when the console build output is set to "Verbose". Changing it to "Normal" fixed it for me.
See this link:
aapt.exe is throwing unhandled exception while building *.apk file for Android project in Eclipse
Try going to Window->Android SDK manager and update Tools and Android 4.0. This solved my issues.
If that doesnt work, try updating everything.
That totally worked for me!
Reference: Error generating final archive: java.io.FileNotFoundException: xxx\bin\resources.ap_ does not exist
Delete bin and gen directories from system. Then F5 in eclipse.
This helped me. Nothing else worked for me.
For me, it was turning off Instant Run.
Preferences -> Build, Execution, Deployment -> Instant Run -> uncheck "Enable Instant Run to hot..."
Also, I heared killing a goat and draw a pentagram on the office floor with its warm blood helps prevent these kind of problems.
i tried the Notepad Tutorial Exercise 2 and got the same error.
i used the wrong API-Level (3). i just switched to level 8 and now it's working fine.
This problem occurred for me after eclipse did some updates. I just went to a backup of my project and took the file that and placed it in the appropriate place in my current project and all worked.
Goto file->Properties and change the target to the correct version of android. For me it was 1.5 (from the tutorial on hack-a-day)
AndroidManifest.xml displayed within Eclipse was out of sync with what was on disk/being read by Android. shutdown restart eclipse and edit AndroidManifest.xml to be correct and clean and build.
Happens due to having two AndroidManifest.xml files and renaming them. Two useful if two apps from same code base. Linking projects with Android is problematic.
I had both values and values-en folders and it was picking the string from the values-en folder. I deleted the en folder and it was back to normal.
I tried
Clean
Delete gen
restart eclipse
Here are a few of the things I did that made this finally work for me.
1) I was using Admob ads, and I didn't have an attrs.xml file in my res/values folder
2) I deleted a line that says "import andriod.R" from my main activity, and all my resources connected again and this ultimately made the error go away.
3) The last thing I had wrong is I had a "lib" folder instead of a "libs" folder that held my Admob jar file.
Lastly, I cleaned the project after these changes.
So, hopefully this helps someone else having this same error if none of the above fix the problem.
I had the same problem and after digging around the different output Eclipse provides discovered that the issue had to do with a malformed 9-patch image.
I discovered the issue in the Problems output (Alt-Shift-Q then X).
I had the same error message and it was caused by having a backslash character in one of my string resource values (in the file: res/values/strings.xml).
I had to remove the offending character and clean the project before it would build.
1 - Try Project > Clean and rebuild project
2 - If clean does not solve this issue, check ALL log in your Console view in Eclipse.
The issue may not be reported at the end of the Console view. In my case, it was a drawable that does not respect the 9-patch format. This was reported somewhere in the Console view but not at the end !!!
Delete any 9 patch drawables created in gimp and refresh.
Delete bin and gen on filesystem.
Refresh (F5) project in Eclipse.
I faced the same issue. And I fixed it by removing newly added png file. It was not able to generate resources.ap file because of one of my png file in drawable.
I got this problem after the upgrade to Android SDK Tools 15. It was also related to the PNG image as some other replies indicate. After analyzing the Eclipse Console output I found out that the process aapt.exe is crashing while processing of one of the images. More precisely it was in the step labeled as "Including resources from package". To identify the file causing the problem I scanned the Console output, found 3 calls of aapt.exe and each of them I re-ran in the Windows Console. The third one ("aapt.exe package -v -S ...") crashed on one of my PNG files. After I replaced this file (in all supported resolutions) the problem has gone.
If you use SurfaceView and have recently changed the name of the package, you might want to check any XML tags that refer to the class.
first try
clean,build automatically from eclipse
and if not resolved then try uder solution
i found solution why R.class not made by eclipse after making again-2 clean,build etc.
problem is here in strings.xml:
Hello World, HelloAutoComplete!
HelloAutoComplete these are by default created by the eclipse when you create an projects
definitly you are changing the strings.xml for your own requirment sometimes you cleare the string.xmls these two lines from your codes.
it is making problem in AndroidManifest.xml file
so it cant communicating strings.xml
dont delete these two lines from strings.xml
android:icon="#drawable/icon" android:label="#string/app_name"
android:name=".HelloAutoComplete"
android:label="#string/app_name"
regards aarifmohammadkhan#gmail.com
if any one have nay problem in android
welcome for asking questions
Regards
aarifmkhan
You might need to remove extra files from your assets or res directory. One case I had was having both "A.jpg" and "A.JPG" files in the assets directory. It prevented the resources.ap_ file from being generated.
For Android studio, if you are using gradle 2.2.2 just disable shrinkResources into build.gradle file:
shrinkResources false
Try run your Eclipse as administrator.
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.
I've found out that my R.java is never updated, so it doesn't contain information about my new resources, so I decided to delete it and thought that Eclipse would generate a new one. But that didn't happen, and I don't have R.java now. How can I regenerate one?
I'm using Windows 7.
From one of the comments: "Doing Project -> Clean is what caused the problem for me. Cleaning deletes R.java...and for whatever reason the plugin is not regenerating the file."
I found this happening to me with a broken layout and everything blows up. Relax, it's like that old mistake when you first learned programming C where you forget one semicolon and it generates a hundred errors. Many panic, press all the buttons, and makes things worse.
Solution
Make sure that anything the R. links to is not broken. Fix all errors in your XML files. If anything in the ADKs are broken, R will not regenerate.
If you somehow hit something and created import android.R in your activity, remove it.
Run Project -> Clean. This will delete and regenerate R and BuildConfig.
Make sure Project -> Build Automatically is ticked. If not, build it manually via Menu -> Project -> Build Project .
Wait a few seconds for the errors to disappear.
If it doesn't work, delete everything inside the /gen/ folder
If it still doesn't work, try right-clicking your project -> Android Tools -> Fix Project Properties.
Check your *.properties files (in the root folder of your app folder) and make sure that the links in there are not broken.
Right-click your project > properties > Android. Look at the Project Build Target and Library sections on the right side of the page. Your Build Target should match the target in your AndroidManifest.xml. So if it's set to target 17 in AndroidManifest, make sure that the Target Name is Android 4.2. If your Library has an X under the reference, remove and re-add the library until there's a green tick. This might happen if you've moved a few files and folders around.
What to do if R doesn't regenerate
This usually happens when you have a broken XML file.
Check errors inside your XML files, mainly within the /res/ folder
Common places are /layout/ and /values/, especially if you've changed one of them recently
Check AndroidManifest.xml. I find that often I change a string and forget to change the string name from AndroidManifest.xml.
Check that Android SDK Build-tools is installed. Window -> Android SDK Manager -> Tools -> Android SDK Build-tools
Make sure when you update the Android SDK Tools, you also update the Android SDK Platform-tools and Android ADK Build-tools. Build fails silently if they don't match.
If you can't find the issue, right click /gen/ -> Restore from local history... -> tick R.java -> click Restore. Even if it doesn't solve the problem, it will clear out the extra errors to make the problem easier to find.
This site suggests:
if you run a clean on the project it should regenerate all the generated Java files, namely R.
...and...
In Eclipse, under the Project menu, is an option build automatically.
That would help you build the R.java file everytime modifications are
made. The Clean... option is also there under Project.
This site suggests another solution.
I had the same issue. When I checked it out I found that the name of the XML resource under layout was not having the correct naming convention. It had some capital letters. So I renamed it to make all letters lowercase and the magic worked.
One reason the R.class can go missing suddenly is when there are errors in you XML files. For instance, when you add an XML file with uppercase letters in the name like myCoolLayout.xml which is not allowed. Or when you have references that don't point to existing files, etc.
In Eclipse, simply use Project --> clean to clean the project. The
R.java is going to be automaticly (re)-created.
If for some reason that dosn't work: Make sure your layout.xml files don't contains errors. Eclipse seems to be a bit buggy here: sometimes it doesn't mark the errors within the XML nor the package explorer. In such a case: Take a look at the "console" or "problems" view after using "clean". All errors should be displayed there. Fix them and redo a clean.
NOTE: It is NOT neccessary to fix the errors you get because of a missing R file! Just fix the XML files and other project errors and use clean!
Quick fix:
The package name in the manifest needs to be the same as the one in the /src folder, the /gen folder package will be automatically reproduced.
Detailed observation:
Observe the name of package in the /gen folder. In my case it was different than the one in the /src folder.
The package referenced in the manifest was that of the /gen folder.
I attempted to add a package with the name of the /src folder to the /gen folder too see what would've happened, but this did not solve the issue. I proceeded then to remove the package name that was not the same as the package name of the /src folder. This package with the name that did not correspond to the /src folder was recreated as soon as I removed it.
Since the package reference in the manifest corresponded to the one that was being senselessly recreated and that did not correspond with the package in the /src folder, this prompted to rename package = "oldPackage" with the package = "srcFolderPackage".
I had the same issue, and I finally found the problem: In the strings.xml, I did not keep the line <string name="app_name">program-name</string> which is present by default when creating a new Android project. I thought it was only used for the program HelloWord, which is the original program.
However, the AndroidManifest.xml refers to this value, hence:
=> A compile error;
=> the R.java isn't updated;
=> ID are not recognized...
Android has added in SDK build tool ADT 22 for the building mechanism. You just need to do the following steps.
Update Android SDK Tool
Update Android SDK Platform Tool
Update Android SDK Build Tool
Add the path of your build tool to the path variable. (path up to---- YOUR DIRECTORY-PATH\android-sdk\build-tools)
This will solve the issue.
If your R.java isn't getting generated, one of the solutions is to delete the layout file named "blabla.out.xml".
After deleting this file, try cleaning the project from menu Project -> Clean.
As a generalization of Glaux's answer, if you have any errors in the res directory, then R.java may not generate - even if you clean and rebuild. Resolve those errors first.
As an example: when you add an image file of say, "myimage-2.jpg", the system will consider this an error, since file names are limited to alphanumeric values. Do a refresh on your 'res' directory after adding any files and watch the output in your console window for any file name warnings.
If your OS is Ubuntu, I can provide some suggestion:
Install or upgrade ia32-lib:
sudo apt-get upgrade ia32-libs
Check if you have the right permission on the aapt folder:
cd ANDROID/adt-bundle-linux-x86_64-20130522/sdk/build-tools/android-4.2.2
chmod 777 aapt
Start Eclipse:
sudo eclipse
Run Project -> Clean in Eclipse
You 100% have an error in an XML-file, but the XML verification does not show you the error. This is the reason why you need to check your XML files first!
It is ALWAYS helpful to take a look at the Problems Tab in Eclipse. In my case, I was getting a "android unable to resolve target 'android-8'" error message that kept the R.java from being generated. So, I corrected the imported target to the one I was using in the default.properties file, then I performed a clean via Projects->Clean and voila! R.java is automatically generated! Hope it helps!
Cleaning project, closing Eclipse, re-opening it and launching my project finally made my R.java to reappear... Hope it helps
Make sure you are not importing
android.R;
R.java will never be generated if there are any errors in the res folder. For example, in the drawable subfolder there are two files which have the same name, one is icon.png and the other is icon.html.
You can see some error in the Eclipse console log window which is saying "Resource entry icon is already defined.". After deleting icon.html, you can clean or just delete the gen folder. You will find that R.java is created.
I've found that any file that has capital letters in the res folder will create this error. This happened to me with a PNG file I added and forgot about.
After reading through many posts and YouTube videos, I found that each of us have R.java missing for different reasons.
Here's how I fixed this in Eclipse:
Create R.java in gen folder manually and save.
After that go to Project and click "Clean"
The following message will display and your file will automatically be rewritten:
R.java was modified manually! Reverting to generated version!
For me, I had linked v7 appcompat twice. Anyhow, in Eclipse, right click the project name in Package Explorer or Navigator, go to Properties, Android, and uncheck any duplicates in the Library section. You may need to Build --> Clean afterwards.
There's obviously no one final answer to this, but here's another one I don't see here already:
I've had R.java disappear after (attempting) a Team Synchronize, and there were conflict resolution files in the project (i.e., thingy.xml.mine,thingy.xml.r35, etc.). Deleting them/resolving the conflicts regenerated R.
I had this problem. Accidentally I deleted this
xmlns:tools="http://schemas.android.com/tools"
which started causing build errors all over the project in my XML files as well as my Java files. As soon as I retyped what I deleted, it worked again :)
OK so it's clear that there can be a lot of causes for this problem. If you're on a 64 bit linux machine and you are just setting up the ADT for the first time, you may get this problem where R is not automatically generating. Check the console tab and you may see an error similar to:
'No such file or directory' while attempting to get adb version from '/home/patrick/code/android-sdks/platform-tools/adb'
If that's the case you need to install ia32-libs, using something like:
sudo apt-get install ia32-libs
See here for details: Android adb not found
I've came across this problem a few times. I found that if I didn't import the package R through my application's name, for example, if my application had the package name example.test then I found that I had to import example.test.R in order to access any of the resources.
If this wasn't imported then the resources that where getting returned were the default resources with none of my own included.
With that said if you find that you are only getting a list of default resources then just check to make sure that you're importing application_package_name.R and not android.R.
My problem was that appcompat was not in the same directory as my project.
I found this out when compiling my app with Ant.
Also make sure that you have the latest version of the ADT plugin, and open the Android SDK manager to update all SDK tools to the latest version. Check for updates in Eclipse itself as well. Non-matching versions caused the problem for me.
My problem was inside a menu file.
The compiler doesn't seem to warn you if strings which do not exist inside strings.xml are referenced in menu files. Check if your items in your menu XML files reference any strings which do not exist in your strings.xml. Usually in android:title.
For me, this error was caused when I tried to duplicate an existing res/menu instead of creating one with the wizard.
All of these answers could not work if you use Maven. The solution for me was to add
<genDirectory>${project.basedir}/gen</genDirectory>
to the configuration section of android-maven-plugin.
I found a solution why R.class is not made by Eclipse after making it again - 2 clean, build, etc.
The problem is here in strings.xml:
<string name="hello">Hello World, HelloAutoComplete!</string>
<string name="app_name">HelloAutoComplete</string>
These are by default created by Eclipse when you create projects.
Definitely you are changing the strings.xml for your own requirement. Sometimes you clear the string.xmls these two lines from your code:
It is making a problem in the AndroidManifest.xml file:
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name=".HelloAutoComplete" android:label="#string/app_name">
So it can't communicate with strings.xml.
I changed my layout XML file name and found out later that of the XML file (widget provider in this case) still refers to the old layout XML which doesn't exist, and that prevented the auto generation/correction of R class.