How to fix "Cannot resolve symbol 'app' " in android studio?

Question

Android studio is showing errors on every line that is related to support library. And on rebuilding the project it says:

Android resource linking failed.

I've tried following:

clean/rebuild
Invaidate caches/Restart
Uninstall/Reinstall Android Studio

My build.gradle(app) is Following:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.androphobia.fyp.spreadknowledge"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        multiDexEnabled true
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    buildToolsVersion '28.0.3'
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.google.firebase:firebase-auth:16.1.0'
    implementation 'com.google.firebase:firebase-core:16.0.7'
    implementation 'com.google.firebase:firebase-storage:16.1.0'
    implementation 'com.google.firebase:firebase-firestore:18.0.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.android.support:multidex:1.0.3'
    implementation 'de.hdodenhof:circleimageview:3.0.0'
    implementation 'com.google.android.gms:play-services-location:16.0.0'
    implementation 'com.github.bumptech.glide:glide:4.9.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.9.0'
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:support-media-compat:28.0.0'
    implementation 'com.android.support:support-v4:28.0.0'
    implementation 'com.android.support:support-compat:28.0.0'
}

apply plugin: 'com.google.gms.google-services'

styles.xml is as Following:

<resources>

    <!-- Base application theme. -->

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
        <item name="colorAccent">@color/white</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

Image of styles.xml in project is as:

Image of results on rebuilding project:

Possible duplicate https://stackoverflow.com/questions/38955002/cannot-resolve-symbol-app — IMParasharG, Apr 17 '19 at 10:12
@Basi thanks for replying I added the image because in code it will not be possible to show errors that android studio shows on rebuilding the project. — Hamza Khursheed, Apr 17 '19 at 10:14
@GovindParashar I have already read that answer but unfortunately did not work for me — Hamza Khursheed, Apr 17 '19 at 10:16
@RanaHamzaKhursheed check [this](https://stackoverflow.com/a/49745282/4649110) for getting build error log — Basi, Apr 17 '19 at 10:20
Delete build folder under app and make sure you didn't add some incomplete code somewhere in the activity, adapter or anywhere else. — Jyot, Apr 17 '19 at 10:37
@Jyot deleted the build folder and sure there is no error in any class except mentioned above but nothing changed same errors. — Hamza Khursheed, Apr 17 '19 at 10:45

score 0 · Answer 1 · answered Apr 17 '19 at 10:15

0

Please try adding this dependency here :

 implementation "com.android.support:support-core-utils:28.0.0"

answered Apr 17 '19 at 10:15

coroutineDispatcher

7,718
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can you pass the style code in the question please ? – coroutineDispatcher Apr 17 '19 at 10:28
https://stackoverflow.com/questions/17870881/cant-find-theme-appcompat-light-for-new-android-actionbar-support And also try this link – coroutineDispatcher Apr 17 '19 at 10:30
check now the question – Hamza Khursheed Apr 17 '19 at 10:37
type `parent="android:Theme.Light"` this instead of your code – coroutineDispatcher Apr 17 '19 at 10:42
Replacing with parent="android:Theme.Light" remove error on only specific line because I think errors are due to appcompat library. – Hamza Khursheed Apr 17 '19 at 10:51
well I would to like @Sejpal Pavan says , but also , I would suggest to migrate to Android x if it is a new project – coroutineDispatcher Apr 17 '19 at 10:57

score 0 · Answer 2 · answered Apr 17 '19 at 10:17

0

remove this two dependency,

implementation 'com.android.support:support-v4:28.0.0'
implementation 'com.android.support:support-compat:28.0.0'

answered Apr 17 '19 at 10:17

Mayur Dabhi

3,607
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score 0 · Answer 3 · answered Apr 17 '19 at 10:33

0

downgrade to 27 and check,or check sdk 28 is installed

answered Apr 17 '19 at 10:33

Sejpal Pavan

130
10

score 0 · Accepted Answer · answered Apr 17 '19 at 12:40

0

Migrating to Android-X resolved the issue.

Go to:

Refactor --> Migrate to AndroidX

answered Apr 17 '19 at 12:40

Hamza Khursheed

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Hardik Bhalala · Answer 5 · 2019-04-18T06:42:50.777

0

1. Close the Android Studio 
2. Delete the .AndroidStudio3.3 folder from File System
3. start Android Studio after that .AndroidStudio3.3 Folder Recreated Automaticall then 
   Your Error will be solved

edited Apr 18 '19 at 06:42

answered Apr 17 '19 at 13:43

Hardik Bhalala

209
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Problem is resolved thanks for you contribution. I upgraded to AndroidX. – Hamza Khursheed Apr 18 '19 at 06:12
Yoo bro !! keep it up. – Hardik Bhalala Apr 18 '19 at 06:38

Basi · Answer 6 · 2019-04-18T12:21:48.567

0

Issue related CircleImageView version and your project.

In Your project your support library version 28.0.0 (pre-androidx) and CircleImageView version 3 which is running androidx version.

so you have to upgrade your project androidx or downgrade circleImageView version to 2.x

edited Apr 18 '19 at 12:21

answered Apr 18 '19 at 12:16

Basi

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score 0 · Answer 7 · answered Mar 25 '20 at 13:16

0

File > Invalidate caches/Restart

Worked for me.

answered Mar 25 '20 at 13:16

Kamran Riyaz

79
2
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How to fix "Cannot resolve symbol 'app' " in android studio?

7 Answers7