Android Studio: Gradle: error: cannot find symbol variable

Question

I was working on my app and everything was normal until I tried to display image in java.

I ran the app once and it ran normally, the picture was displayed. After that it asked me to import some libraries and I imported them. After that I got errors for my activities.

Errors like:

Gradle: error: cannot find symbol variable activity_main
Gradle: error: cannot find symbol variable button1
Gradle: error: cannot find symbol variable button2
Gradle: error: cannot find symbol variable textView
Gradle: error: cannot find symbol variable secondActivity

In MainActivity I have imported these libraries:

import android.R;
import android.content.Intent;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.Button;

and in secondActivity these:

import android.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

Does anyone know how to fix this?

EDIT: I deleted import android.R; and now it works normally.

A Gradle resync fixed this for me. – akiraspeirs Feb 10 '15 at 03:47 — akiraspeirs, Feb 10 '15 at 03:47

score 75 · Accepted Answer · edited May 23 '17 at 12:03

75

You shouldn't be importing android.R. That should be automatically generated and recognized. This question contains a lot of helpful tips if you get some error referring to R after removing the import.

Some basic steps after removing the import, if those errors appear:

Clean your build, then rebuild
Make sure there are no errors or typos in your XML files
Make sure your resource names consist of [a-z0-9.]. Capitals or symbols are not allowed for some reason.
Perform a Gradle sync (via Tools > Android > Sync Project with Gradle Files)

edited May 23 '17 at 12:03

Community

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answered Aug 09 '13 at 20:00

BLaZuRE

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Manually declaring the "import com.your.app.package.name.R" fixed the "cannot find symbol variable" for me. But this was after i had copied a class from a module into the main app project in Android Studio and Gradle failed to build. But I would suggest trying the above options first, as that is the likely case for this error. – TouchBoarder Oct 31 '15 at 15:32
2

I had similar problem currently. The problem was that in my project I had more modules. E.g. `com.packagename.app` module and `com.packagename.library` module. Although both, the class and the `R.string` resource were from the `com.packagename.app` module I somehow had `import com.package.library.R` in the class. Somehow Android Studio did not recognize this as an error and Gradle/Sync build my project without problems. But when I tried to run Unit Tests Gradle build failed with the described error. Removing the `import com.packagename.library.R` solved my problem. – Jan Kubovy Jan 17 '16 at 09:06
Note: underscore `_` can also be used in resource id's – Nino van Hooff Aug 04 '17 at 08:49
Actually, you do need to import R if the class you are working on is not in the application package. – Brill Pappin Nov 29 '17 at 14:45
You just saved me. I moved a class from a module to main app folder and also the strings from the module and I couldn't understand why the strings are not found in the class I moved. Issue: the class imported R from the module, not from the app. Thanks a lot! – sunlover3 Jan 22 '18 at 11:12

score 25 · Answer 2 · answered Jan 04 '16 at 13:12

If you are using multiple flavors?

-make sure the resource file is not declared/added both in only one of the flavors and in main.

Example: a_layout_file.xml file containing the symbol variable(s)

src:

flavor1/res/layout/(no file)

flavor2/res/layout/a_layout_file.xml

main/res/layout/a_layout_file.xml

This setup will give the error: cannot find symbol variable, this is because the resource file can only be in both flavors or only in the main.

score 23 · Answer 3 · answered Dec 30 '16 at 06:43

If you are using a String build config field in your project, this might be the case:

buildConfigField "String", "source", "play"

If you declare your String like above it will cause the error to happen. The fix is to change it to:

buildConfigField "String", "source", "\"play\""

score 2 · Answer 4 · answered Mar 19 '19 at 13:33

2

Open project in android studio click file and click Invalidate Caches/Restart

answered Mar 19 '19 at 13:33

RanaUmer

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5
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score 1 · Answer 5 · answered Jan 04 '18 at 15:53

1

make sure that the imported R is not from another module. I had moved a class from a module to the main project, and the R was the one from the module.

answered Jan 04 '18 at 15:53

Alberto M

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score 0 · Answer 6 · answered Jul 13 '17 at 22:14

Make sure you have MainActivity and .ScanActivity into your AndroidManifest.xml file:

<activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".ScanActivity">

    </activity>

score 0 · Answer 7 · answered Aug 13 '17 at 08:07

Make sure your variables are in scope for the method that is referencing it. For example I had defined a textview locally in a method in the class and was referencing it in another method.

I moved the textview definition outside the method right below the class definition so the other method could access the definition, which resolved the problem.

score 0 · Answer 8 · answered Apr 26 '18 at 01:46

0

Another alternative to @TouchBoarder's answer above is that you may also have two layout files with the same name but for different api versions. You should delete the older my_file.xml file

my_file.xml
my_file.xml(v21)

answered Apr 26 '18 at 01:46

Bond James

33
2

score 0 · Answer 9 · answered Mar 23 '21 at 02:01

Make sure that the control you are referring to in the XML layout file really exists, even if it's not being used.

I had this after when I did "removed unused resources" refactory.

For example, you will get this error if there is no progressBar in the layout.

rootView = inflater.inflate(R.layout.fragment_stats, container, false);

mProgressBar = rootView.findViewById(R.id.progressBar);

score 0 · Answer 10 · answered Jun 11 '21 at 06:28

0

Please check you accidentally added the XML file into the layout folder.

answered Jun 11 '21 at 06:28

jerald jacob

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score 0 · Answer 11 · edited Nov 27 '21 at 15:29

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Make Sure your package name correct at top, wrong package name may cause this issue.

edited Nov 27 '21 at 15:29

Marco Bonelli

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answered Nov 27 '21 at 15:11

fazal ur Rehman

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score 0 · Answer 12 · answered May 17 '23 at 12:11

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Check if it's an interoperability issue, for example, the class not found may be a .java file not .kt

answered May 17 '23 at 12:11

Lucas B.

489
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Android Studio: Gradle: error: cannot find symbol variable

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