All of a sudden I am getting red underlinings under my references to elements e.g R.textboxID. I did some googling around and I found that the error occurs when Android Studio can’t generate your R.java file correctly.
My question is how does Android Studio just suddenly not know how to generate my R file correctly when it was generating it well all along? How can I fix this problem permanently?
Select Build > Clean Project from the Android Studio toolbar, wait a few moments, and then build your project by selecting Build > Rebuild Project.
If a single clean/rebuild cycle doesn’t work, then try repeating this process a few times, multiple clean/rebuild cycles in quick succession usually work.
This usually happens when some unexpected event, like an IDE error occurs and the project needs to be rebuilt. Just hit Build -> Rebuild Project.
Sometines this may occur after you modify your build.gradle file, and sometimes, if it only occurs within one of your classes, you might not be inflating it correctly.
Gradle sync succeded? Try one of the following:
Clean end rebuild your project
From Android studio menu: File->Invalidate cache/restart, then clean and rebuild project
If none of above helps, close Android studio and remove ~/.gradle directory. Then run Android Studio, open your project, wait for finish sync, then rebuild project
Also make sure your gradle configuration is correct and resource xml files syntax is correct.
Please check the import statements at the top of file some times there may be import com.android .R will be there so you should delete that statement and it will work fine
Related
I'm working on a new app in AndroidStudio, everything was working fine, I was testing the app on my phone, etc.
Then at some point AndroidStudio gave me a popup in the lower right corner, something about Gradle. I didn't quite understand it, and hit Accept or something like that. Then suddenly something happened to all my projects in AndroidStudio (not just the one I was working on):
All build modules are gone.
I can't make any new build modules, because "Error: Gradle project sync failed. Please fix your project and try again". I never synced anything with Gradle previously, why do I suddenly need to do something like this?
Clicking "Sync project with Gradle files" doesn't work: "Plugin [id: 'com.android.application'] was not found in any of the following sources". Where does "com.android.application" even come from? I never added any plugins anywhere.
"Everything" is wrong in all my Java files, I even get "Cannot resolve symbol 'AppCompatActivity'" and "Cannot resolve method 'OnCreate(android.os.Bundle)'". Wtf?
All my Java files have this red symbol, which says "Java file outside of source root". Why are they suddenly in the wrong place?
Nothing is working anymore, restarting AndroidStudio doesn't change anything, switching project doesn't change anything, and where did my build modules go?
How do I make this go back to normal?
Try:
Build -> Clean Project and then Build again
File -> Invalidate cache/restart
check your run/debug configuration in the top toolbar, it should be app by default.
I have encountered issues in my android studio regarding java classes/symbols not found, despite these classes and symbols being placed in the same directory, or under the same parent directory. I am making use of the DJI's mobile SDK for android.
Example of errors:
Cannot resolve symbol 'DJISampleApplication'
For illustration, here are 2 screenshots
First example. Clicking on "import class" causes android studio to create a brand new class instead of linking it to the existing one.
second example
However, oddly, when I go under "Build >> Make Project" , or "Run" to deploy on a real android device, the app can be installed, and there are no errors (only warnings).
Things I have tried:
Uninstalling and re-installing android studio
copying the whole project from the original files in again
Trying on another computer, which works. However, as i am only assigned this pc, i have to get this to work here as well.
Thank you in advance !
Your best bet is to invalidate caches and restart. Solves 99% of problems like this for me.
You can also try to reimport the project using the gradle tool window ...
Click the reload button here ...
I was following the instructions online in android app development course for beginners and I encountered this problem.
The instructor was demonstrating how we could use the layouts we created for the activity. He was able to find the layout he created using R.layout., but I could not.
The activity_main_listview.xml is the View that I created. I am an absolute beginner so I don't know what is wrong here.
Is there any way I could resolve this problem?
I have tried to Synchronize both the .xml files and the MainActivity.java file. I have also tried to clean and rebuild the project.
This is a picture of the part where it did not work
This is common problem which occurs with Android Studio!
Its not your problem, it is bug of Android Studio!
To resolve this, Just Clean your project and Restart Android Studio!
I had the same problem, fixed by replacing R with com.example.appname.R obviously put your package reference in there instead. Or just add this line to your file:
import com.testapp.activitydemo.package.R
Or even better, try removing this line from your code if exists:
import android.support.compat.R
If your XML's contain errors your generated file might not build try erasing most of their content and making sure id's and file names are not duplicated and no capitals and spaces are used. If it works you can start adding stuff.
Another note:
Sync Project With Gradle File Once you update the Gradle plugin you need to sync project with the Gradle file. Open android studio and click on Files > Sync Project with Gradle Files option.
Clean and Rebuild Project The most effective solution is the simplest: clean and rebuild your project. Select Build > Clean Project from the Android Studio toolbar, wait a few moments, and then build your project by selecting Build > Rebuild Project.
Can anyone explain to me the cause of this error? I know what is dexpath and dex class in android and how to fix this error. but don't know what is the cause of this error popping up every now and then.
This error occurs when
I transfer my project from one pc/laptop to another pc/laptop.
Whenever I've updated my android Studio lets say from AS 2 to AS 3 canary or stable release.
Uninstall and reinstall the Android studio and try opeining the Project again.
How I'm Fixing it:
Just remove all the dependencies and everything related to DEX Class file from gradle and sync it and then revert back to gradle settings with all the DEX file and dependencies added and Sync again. VOILAAA ..
And this is really annoying. How I can avoid this issue for my other projects without going through all this gradle sync tweak.
I had the same issue with moving projects to different system. when you move your project folder just leave out the build folder and you'll not see the error next time.
The error says a lot more then just class not found exception in the log. The path of the files/ app-parts.apk gets invalid when you move your project to a different system.
Just don't copy or just rename the old build folder to something else and open your project in AS. Build->CLEAN , BUILD->REBUILD and everything will work.
Happy Coding..
I'm creating a clean project on ADT and I noticed that the gen folder is empty (with no R.java in it), not letting me run the project. I'm running ADT with all stuff up-to-date (as you can see here)
I already cleaned and built it in every possible way. I also tried to reimport the project, and nothing. There are no errors in the XML files.
I searched for a solution and I found a lot of people with the same problem, and in most cases the solution was to update the SDK tools, but it didn't work for me.
Is there a reason for this?
at the top of screen, click build -> rebuild project
Give it a few seconds. it worked for me, i hope it save you aswell
im using Android Studio(beta) 0.8.9
My R disappeared after i fiddled with sound files in my res/raw directory(converted them to different formats, figuring out how SoundPool class works...and suddenly there is red "R"'s everywhere!
Try right clicking on the project, then going to Android Tools > Fix Project Properties.
If that doesn't work, then try cleaning it before and possibly after that.
If R.java disappears, you usually have to recreate the project from scratch again.
There are many reasons for R.java missing issue, i use to face this issue frequently, some of my thoughts to debug this issue.
Try creating another test project using File->New->Project->Android->Android Application Project. After creating the project run the project in emulator. If every thing works then your setup is perfect.
Check your imports section of your java files, some times default R.java gets included which is from android package. In this case Remove that import and add correct import statement.
Check your "res" folder all the xml's should be well formed and valid.
Hope these debugging steps may help to find the root cause.
try deleting the r.java file in gen folder. when you run again after cleaning and building the project. It should recreate those files and it should work after that. Try that.
Other wise you might have to reinstall Eclipse as you have tried in so many different projects
Something I just noticed was that after I removed the auto-generated code for the menus (which I wasn't using) it started causing errors. Eventually when I cleaned with the menu xml's still in the file structure, my R file disappeared. I removed all entries in the menu folder and then cleaned again. This worked for my specific instance. Hope this helps others as well.