Develop Reference

Android Studio sudden appearance of unresolved symbols after pulling from Git

I am new to Android development so I apologize for anything I forget to clarify. I am working on a group project in Android studio, checked out from Git. I previously was able to build the project fine, but after a recent pull I suddenly have many compilation errors coming from the package
projectname\tess two\jni\com_googlecode_tesseract_android\src\java\com\google
It seems that I have a big mess of unresolved symbols, like "cannot resolve symbol (piccolo2d, Color, event, swing), which appear at import statements like these at the top of my classes underneath this project
import org.piccolo2d.*;
import java.awt.Color;
import java.awt.event.*;
import javax.swing.Timer;
I am wondering what might cause these unresolved symbols. I have tried deleting the project and re-pulling it from Git, re-building the project, etc.
Any help or direction would be great, I realize I did not give a lot of context, mostly because I myself am confused at where these problems could suddenly come from.

Anything related to awt or swing will inevitably fail; those toolkits are not available on Android. Someone or something is accidentally importing symbols from the wrong place. It's probably android.graphics.Color you want instead of java.awt.Color, etc.
I suspect that if you delete those imports, and then select Optimize Imports from the Code menu in Android Studio, the correct symbols will be imported.

Errors when importing someone else's projects - Android/Eclipse

I have been using Eclipse for about 6 months now, and I noticed that I rarely can import someone else's project into Eclipse. I get so many errors in many files. For example, I tried to import a friend's project that I know works just fine, but I get a lot of "R" errors, like Eclipse can't recognize "R" as a field, and then other weird ones like ActionBarActivity is not recognized or an entire imports like android.support.v4.app.Fragment that visually are in the library but are not being recognized by Eclipse as being there, and I check them and they are definitely marked "Is library" and added properly to the project. Anyone know why this is or how to fix? It's frustrating because to learn, sometimes you need to see someone else's app run first, then look at their code, but you can't. Thanks in advance.
My usual way of importing a project is to do File -> Import -> General -> Existing Projects into Workspace. Also, I have tried cleaning the project, but it doesn't work.

try this File -> Import -> Android -> Existing Android Code into WorkSpace ->then browse-> select your project->make sure the checkBox"copy the project into workSpace" is marked

Check your Build Path. In the Android Section, try using some other API level click on Apply and after your project finishes with the building workspace, again revert back to the original API and click on OK.
Also check for any Build Path errors.

So thanks to the help of everyone of this post, and others on another post, the problem was finally fixed and took several steps.
Turns out that the ActionBarActivity error had a quick fix (hover over it, you get quick fix options) of importing the appcompat_v7 library. I never chose that before, because I thought it was already installed, hence the conflict with android-support-v4.jar (meaning there were doubles of that library), but I chose to import it anyway and that error went away.
But I discovered that android-support-v4.jar was actually a component of appcompat_v7, so that was causing the "Jar mismatch!" error in the console. So I deleted android-support-v4.jar from the libs folder, and the jar mismatch went away.
Lastly, my layout files were all not being recognized, even though I knew the variable names were all correct. So the error was from when I tried to refresh my imports in the very beginning of the problem (using shift+command+O), thinking it was an import problem (which it was), but at that time, refreshing did nothing. BUT... Eclipse took away import com.laurengariepy.android.gridimagesearch.R; and replaced it with android.R;, which is what was causing all the layout errors. So once I put that com.laurengariepy.android.gridimagesearch.R; back, then all errors went away.
So the take-away to this story, is be careful with Eclipse version 22.6. The auto-import of the appcompat_v7 library will cause a lot of trouble when you try to import other people's projects, because they were likely not created in an IDE with appcompat_v7 already there.

The import com.example.myfirstapp.R can not be resolved

I have been working my way through the Tab menu tutorial and have come across multiple errors. After doing some research on here I found the common solution was to change the Import android.R to import com.example.myfirstapp.R.
This is giving me the error that this file cannot be resolved. Can anyone tell me why I can't import this file? I have a hunch from researching on here that eclipse has not built the file, but I have no idea how to build it as I am new to coding as this is just a hunch and may be completely wrong.
package com.example.myfirstapp;
[Edit}
i have removed the "com.example.myfirstapp.R" and have CMD-SIFT-O to restore the imports but i still have the following errors.

You don't need the com.example.myfirstapp.R unless it is in a library. If it is in com.example.myfirstapp, remove it.
Also, trying cleaning your project and rebuilding it.

Make sure you don't have any files, pictures, etc in your drawable or assets folder with capital letters, spaces, or dashes. Just use plane old lowercase. Also, try to clean your project. Go to project > clean. Then restart eclipse. Hope this helps. Also eclipse won't reconize any changes in XML files without saving first. Make sure to save after you add a button, ect.

R cannot be Resolved To a Variable only in one line

My friend created an android application using phonegap, jquery and facebook sdk in eclipse. I wanted to run the application in my computer. So I imported the whole project into eclipse. I downloaded all the necessary APIs. Initially I got a lot of errors, but I solved most of them.
Now I am stuck with just one error. And it is in the src/com.facebook.android./FbDialog.java file. One particular line
Drawable crossDrawable = getContext().getResources().getDrawable(R.drawable.close);
gives the error R cannot be resolved to a variable.
I have gone through a lot of similar questions on this website as well as other websites. I have cleaned the project innumerable times. The R.java file builds successfully. Also, my friend is not getting any error when he runs the same project in his laptop. So I don't think there is any problem with the coding part.
I am definitely missing some important setting or download. Please help. This one error is giving me a lot of headaches.
I am a new user her so cant upload a screenshot.

1st. res/drawable folders (ldpi, mdpi, hdpi) must contain an image named close, if not add it. I doesn't really mater, in order to overcome the error, in which of them the file exist.
But in order to use resourses properly see the Android documentation here
2nd. File FbDialog.java must have an import of the R.java sometimes the R imports get mixed with clean & built and instead of import your.package.com.R; it is included the import android.R;
Depending on the dependency libraries or related projects of main project the close file resource may be a part of an other library in that case you will need import that.package.com.R;. So if it is part of Facebook SDK then you will need import com.facebook.android.R;
I hope you get the logic of how R imports work.
Update: Lets force it to work, change line to:
Drawable crossDrawable = getContext().getResources().getDrawable(your.package.com.R.drawable.close);

R file is missing android

i was using Eclipse Helios but due to performance issues i changed to Eclipse Galileo and installed the ADT plugging, and added my sdk folder to Elcipse Preferences. Now R.java disappeared from all of my projects. How can i fix this, i did Project/Clean but that won't generate the files, there's nothing wrong in my xml and there's no out.xml in any of my projects.
Thanks in advance

In my experience there is a mistake in the xml somewhere. Eclipse will no doubt tell you where. After I fix the error R appears.

Sometimes when you clean your project the R file disappears, I had the same issue.
The way I fixed it was:
-Make sure all the "import android.R" was removed
-Clean again (if this doesn't fix it, restart eclipse and try again)
Or
-Put the pointers to R file in comment f.e. // setContentView(R.layout.main);
-If all the pointers to R file are in comment, you should get only warnings in the file, and hopefully errors somewhere else.
-Fix the errors and then uncomment the pointers. Sometimes eclipse ignores some errors and drops the R file and then says nothing about it, which is annoying, but this will fix it. :)
-If this still doesn't work, you can try create a new project and copy paste your code in it.

I had this same issue today and figured it out. The reason this happens so often when including external/example files is because often times these examples reference layouts in your application, but do not have access to the package and therefore cannot see the R.java file in that package. to make things clear, here's the beginning of the R.java file:
/* AUTO-GENERATED FILE. DO NOT MODIFY.
*
* This class was automatically generated by the
* aapt tool from the resource data it found. It
* should not be modified by hand.
*/
package com.conceptualsystems.dashboard;
public final class R {
public static final class attr {
}
public static final class drawable {
public static final int csc_logo=0x7f020000;
public static final int icon=0x7f020001;
}
public static final class id {
public static final int activation_code=0x7f070012;
public static final int alpha_bar=0x7f07000b;
public static final int alpha_label=0x7f07000a;
notice the package name is whatever the package name of your application is. .java files that are not included in this package (ie, your example code you just dropped in) will need to explicitly reference that package file like this:
package com.example.android.apis.graphics;
import android.app.Dialog;
import android.content.Context;
import android.graphics.*;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.SeekBar;
import com.conceptualsystems.dashboard.R;
the last line is the one to pay attention to. after importing the resources explicitly, the resources will be available in your example code.

created new project in eclipse, then I imported the sample files into it, yet still same error. You might want to try the following:
In Eclipse -> Right Click on Project -> Android Tools -> Fix Project
made sure that all resources are lowercase.

Try unclicking and re-clicking build project automatically in the project dropdown, closing the program each time. There have been know bugs about this for a while but there's not always a set fix.
When it once happened to me it turned out it was because i'd named an .xml file with a capital letter. Worth checking.

I had this problem when upgrading from Eclipse/Helios to Eclipse/Juno.
I set up the IDE and then imported an existing (working) project. If I then ran it in the emulator it ran but in its original version although the java code was for the latest version.
I then did a Clean (as explained in many other posts) and a (re) build but then ended up with host of errors due toSmissing R.java file.
The problem turned out to be some 'errors' in the layout xml files which had not been recognised by Eclipse/Helios. Specifically, in my case, there were some layout_width='match-parent' (and height) settings which Juno objected to. I tried changing those directly in the xml files but Juno wasn't having it and still reported it as a 'match-parent' error (although it had clearly been changed).
The only thing to do was to go to the graphical layout, right-click to get Properties and then change the Width and Height properties there. Also, as they were already showing as 'fill-parent', I had to first change them to 'wrap-content' and then change them back to 'fill-parent'.
Once I'd done that for all instances of 'match-parent' I could then do a build and run the latest version in the emulator.

There are mistakes in res. Once I have the same xml files in layout and menu, generate failed, no R.java generated.

Localize the correct R. package import, should be in your packages.
ex. import com.yourdomain.test.R;

This is where ADT Android project is a bit different from a normal Java project. An android project requires a constantly updated persistent R.java file. Among other things, the R.java file has all the resources IDs provided in your App and maintains interface's consistency.
So first make sure R.java file is being generated for your android project.
To find that out first go to the top of ADT (Eclipse) and clean the project PROJECT->CLEAN
If the 'Build Automatically' is checked the R.java file should be created now.
To confirm, you can simply search the file in the project folder. You won't find it if its not being created.
If R.java is not being created, there is 90% chance that there is some issue with one of your interface *.xml files. Which usually resides in res->layout->activityXXXX.xml
Fix the interface file/s (try making it very simple with a single button or something) and R.java file will be generated by ADT automatically. At this point you should start noticing R.layout.XXXX not found type errors in your main program/activities. Which is a good thing, because now you can create/rename correct layout items and fix your project.
Just my 2 cents....

same happened to me, corrected checking any errors in res xml files, and changing target 1.5 to 2.2 android (on my case)
this usually happens to me when importing external code or online source code from examples or other developers.

Hi I had this happen to me this weekend.
The actual reason this had happened was that I had unchecked the update option for Android in the preferences as it wasn't working with the previous version of Eclipse. Now although the eclipse was seeming to run fine, when I PROJECT->CLEAN the project the R.java was missing.
Try re-ticking the android update option (WINDOW -> PREFERENCES -> INSTALL/UPDATE).
This completely solved my issue and I did not have to both with any hassle of scanning each line of my many xml files or my image resources.
Hope this helps someone :)

I just Encountered the same problem.
Turned out my Source control had inserted an Addedd>>>>>>>>>>>>>>>> section to my mainifest file.
All I had to do was fix the manifest file and then all the errors disappeared.

This happened to me while adding some new resources to my project.
The R file is build after every resource update.
The error in my case was incorrect file name. One of the image resources had a capital case letter in its name and that prevented the build from creating the R file. Changing the name simply worked.
I would suggest that when you add too many resources at a time, just make sure of the naming conventions for them. Its easy to miss such things.
Resource conventions: http://developer.android.com/guide/topics/resources/providing-resources.html

I had the similar problem. That was because I saved a drawable file picture.jpg as picture.png, as soon as I changed the name to previous one it started working. hope this would help someone in future