I added some UI elements to the main.xml file in the res\layout folder and when I try to access them through the call, R.layout.my_uielement, the UI element that I created is not there. Even when I add a new xml file with UI elements, it still doesn't show up in the R.layout class. I have made checked the ids on them and they have the correct format (I think): android:id="#+id/my_button". What could be the problem? Do I need to compile the code first?
UPDATE:
I have already tried adb kill-server then adb start-server. It doesn't seem to help. I have also tried R.id.my_uielement, it doesn't register either.
This may not be the case for you, but sometimes when I use something from the android.R package (default android resources) and I use it in my class before making reference to anything from my own resource package, Eclipse adds the import android.R; statement in my imports. This will conflict with the default behavior of implicitly looking in your package's resources.
Check your import statements for import Android.R;. If it's there, remove it. And, if you're using anything from android.R, fully qualify it when you use it in code.
Clean project works fine. In Eclipse if you just change some xml components, it doesn't always generate a new R file. Cleaning does it.
Use R.id.your_ui_element, not R.layout.your_element
I faced this problem too. The R.java was neither generated nor updated.
If R.java is not generated when you create the project, run your 'empty` project. An R.java with references to resources will be automatically generated.
If R.java is not getting updated, Check for updates in Help -> Check for Updates
in Eclipse and update your SDK and ADT if required.
After 2 days I found a way to fix it...
I had saved half done project in my mail, so when R.java vanished i just replaced it with the old R.java file, this fixed a lot of errors, then made necessary changes and built the project(build it not clean)...I do not know whether clean and build performs the same job or not..but everytime i cleaned it , R.java used to go invisible...
Clean is working because it BUILD the project after cleaning. So the problem is ( at least it was in my case, because I switched off the Automatic Build a few days earlier ) that after you add an item or anything in a .xml file, the eclipse doesn't build it and can't refresh the R.java .
I've noticed that my R.java file is not always being properly updated when I add items to my strings.xml file or elsewhere. If I use a new value I added like R.string.newString the actual integer value might still be pointing to R.string.oldString or whatever (it seems to usually be the element directly above or below the new element in strings.xml but I haven't nailed down the pattern for sure yet).
You're not supposed to modify the R.java file, but it doesn't say anything about deleting it (not that I've seen, anyway). I've found that deleting R.java usually fixes my resource-related problems because Eclipse immediately regenerates the file with the integer values properly assigned.
Please note, I'm very much a beginner at Eclipse so I may not understand the consequences of deleting R.java but it seems to be working well for me so far. If what I'm doing is very bad, please let me know.
None of these worked for me!
The only way i can access an #+id/foo is by myPackage.R.id.foo.
Related
I have the exact same issue as the following: dex file does not contain MainActivity class
Since I cant ask for extra help on that thread I have to recreate one.
My comment:
"I still have the same issue. Its an copy older Cordova project (which I recently updated for one client, without any issues). I renamed the project; changed up some resource files, and now I keep getting the same issue as the initial thread creator. I tried all the suggestions, None seem to work for me. Any clues on what is happening, would I need to change around more then just the name and bundle id's. The main activity is linked to the correct name, but when the APK is build and I go open the apk in android studio, it does not show me the folder for the app 'name' where the mainactivity should be.
I do not have the 'gen' folder. So I cannot remove that, unless these are special folders you can only see at some point?"
Im getting fairly frustrated, I checked all the project files for the build that is not working and a working build [2]. I tried to reproduce the issue with the old build, but that one just seems to work. If I make an exact copy of that build, change up the bundle id's [1]. It just doesnt work.
[1][2]: https://imgur.com/a/WnyJTVD
EDIT: The fix that worked for me was: Changing the bundle ID; I assume that the name contained something ilegal? The thing I changed in the bundle id was: 'com.companyname.cvs' The thing that broke it was the 'cvs'. As soon as I renamed it, and reproduced the steps I did before, it fixed it.
An excerpt from the documentation :
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.
My question : WHY? Why does eclipse keep on doing this?
I have been developing Android applications using Eclipse for a quite some time now but I have never been able to understand why eclipse does such a thing.
When I use Ctrl + Shift + O to organize my import statements, import android.R gets added automatically. And all of a sudden my correct code is suddenly covered in red errors, saying that R cannot be resolved. It can get really scary for a beginner as he has no idea what he did wrong.
In another scenario, suppose there is something wrong with my layout files and R.java is not being generated, it says that R cannot be resolved, as R.java has not been generated due to the errors. As I move my cursor to any of the errors, it suggests me to import android.R.
After working on Android for quite sometime now, I know that never to import android.R, but what I have never been able to understand why eclipse keeps on suggesting it, as frankly speaking, adding import android.R never solved any problem of mine. It just added to the existing problems, which used to be really painful during initial days of development.
So, does anyone know the reason behind eclipse making the suggestion to make an incorrect import? Is it just a bug? I don't think it's a bug, as it would have got fixed at least after it was mentioned on the Android documentation.
If it's not a bug, then what is a real purpose of android.R? What does it exactly refer to?
Your opinions/experiences will be really helpful!
Thanks!
This is not a bug. There are a few instances where android.R can be helpful and solve problems.
android.R is an R.java file like the one you have in your own projects. The one in your projects (your.packagename.R) holds references to the resources you have under your /res folder like layouts, drawables, XML files, raw files, strings etc.
On the other hand, the android.R file holds references to certain default resources that Android has inbuilt, like simple_list_item_1.
Eclipse suggests this and auto imports this sometimes as if your project's R file hasn't been generated due to an XML error or something, your code will be referencing a file that doesn't exist. By importing android.R, eclipse makes sure your code references a class that exists. However, android.R is unlikely to have the same resources you did, and this will raise another set of errors.
Eclipse will also always try to automatically import android.R in your class if you rename your package name via android tools and not rename base package name in your code with the same name because he will assume you have two R's in your file.
Try this...
Window -> Prefs -> Java -> Editor -> Save Actions
Uncheck "Organize Imports." Hopefully that will do it.
After this setting, it works for me.
I have tried literally everything to figure out why no new layout files are being added to my R.java file in eclipse. Nothing is working.
I have:
Restarted Eclipse
Used Project>Clean
Deleted R.java (had to restore because it would not autoregenerate no matter what I did)
Ensured all methods are defined in SDK version
Rebuilt the project
Unchecked auto-build
Every combination of above options
Been tempted to throw my computer across the room
Does anyone have any suggestions?
Check you don't have any errors inside one of your xml files. That is, check not only for xml file name errors but also for errors in the xml code, for example an illegal attribute, a forgotten tag etc. Check this in all your xml files, not just layout files but also anim, xml drawables etc. These errors don't show up in the error log but will prevent the R.java from being generated.
When I experienced the same issue as you this was often the reason. The error highlight was only visible inside the file, not the error log.
Net, go through every xml file with a fine comb.
I faced this kind of problem many times. From my thoughts it is caused due to the problem of images in the drawable or case sensitive of layout file (everything should be small). Check your case sensitive of layout file.
I will give all possible solutions that i had done when something like this happened with me
Project-->clean
Check for library if there was any for that
RightClick-->Properties-->Android-->add
Restart Eclipse
Check in
the manifest for if you have many packages make sure u are using the
activity declared package.
I would check the imported R. The problem could be that you have
import android.R;
instead of
import com.myproject.R;
Project -> and check Build Automatically
Is there any error in your resource files? If there is any error in your resource files the R file will not be generated.
When first of u go on Project->Clean the your application then refreshing and auto genrated R.java file for your apps.
Not to be repetitive, but did you check the Android manifest file? The error there doesn't usually pop up.
Did you check for other locale letters (maybe whitespaces too?) in the filenames? Letters that look exactly like Latin.
I think I had similar problem with the names. You can try rewriting your files' names.
Project Explorer (Right click on your project) -> Build Project
This worked for me.
R.java is not responding. I made 4 layouts in res/layout and it took 3 layouts but not responding for 4th
If i edit the R.java will it stop regenerating the code ?
Project > Clean...
This will force Eclipse to delete and regenerate the R.java file.
Just came across same problem. Delete
Import android.R;
This should fix the problem and have all references re validated.
Check all of your resources for errors. Make sure there are no subfolders in your Drawable folders, make sure all resource names contain only lowercase letters, numbers, and underscores for their names, make sure any ninepatch images you're using are correct (use tools/draw9patch in your SDK folder). Clean your project after any changes to these.
If you can't find anything that looks out of place, start removing any resources you've added, removing the most recent first, and cleaning after each removal, and see if the problem goes away. If it goes away after pulling one out, then there's a problem with that resource.
Eclipse is complaining about my Android project saying all my references to resources are unresolved, even though R.java does exist. For example:
signin_btn=(Button)findViewById(R.id.signin_btn); signin_btn.setOnClickListener(this);
I definately have signin_btn defined in my resources. Dont know why Eclipse is not seeing my R class anymore. How to fix?
The thing that happens to me once in a while is that Eclipse decides to "help" me by adding the following statement to the top of the source file:
import android.R;
This means that all non-absolute references will now be matched against the Android built-in resources, instead of your own. Something like "R.id.layout" is now supposed to be in "android.R.id.layout" and not in "com.mydomain.myproject.R.id.layout". Just remove the line.
It happens to me, this is what I think happens:
Whatever process generates R.java starts at the top of your resources and works to the bottom. If it encounters an error somewhere, it just stops... leaving whatever resources haven't been added to R.java out. This is why some of them will say "unresolved", and others will be fine.
It seems that every time you save a file in your project, it regenerates R.java (maybe it's just the files in res/), so you probably fixed whatever the generator broke on, and when you saved AndroidManifest.xml, it regenerated R.java.