Android build success but cannot resolve R

Question

help me, my Android cannot resolve symbol R( the R becomes red color) but when i try to build project, it succeed. anybody know why ? i already try clean project, rebuild project, sync project with gradle files and also invalidate cache and restart but still cannot resolve R

here is my gradle (app):

apply plugin: 'com.android.application'
android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.justinjunias.stockitem"
        minSdkVersion 24
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

apply plugin: 'com.google.gms.google-services'
dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    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'
    // Butterknife
    implementation 'com.jakewharton:butterknife:8.6.0'
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.6.0'

    //Design
    implementation 'com.android.support:design:28.0.0'
    //Volley
    implementation 'com.android.volley:volley:1.1.1'
    //Firebase
    implementation 'com.google.firebase:firebase-core:16.0.8'
    implementation 'com.google.firebase:firebase-database:16.0.6'
    implementation 'com.google.firebase:firebase-auth:16.2.0'
    implementation 'com.google.firebase:firebase-firestore:18.1.0'
}

And my gradle build:

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {

    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.3.2'
        //Firebase
        classpath 'com.google.gms:google-services:4.2.0'


        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

[“cannot resolve symbol R”](https://stackoverflow.com/questions/17054000/cannot-resolve-symbol-r-in-android-studio) is the most common error when building Android apps (for beginners). We need to see the errors to isolate it. — Jon Goodwin, Mar 25 '19 at 02:38
If you are added all your dependencies well,do invalidate caches and restart Android Studio.Perhaps it will works. — Rahul Kushwaha, Mar 25 '19 at 02:49
when i run the application, it succeed but the R is still red/cannot resolve — Jin Asterich, Mar 25 '19 at 02:53

score 3 · Accepted Answer · answered Mar 25 '19 at 03:12

3

Option 1: Update Android Studio to 3.3

Option 2: Update Gradle Version in Project Level build.gradle

classpath 'com.android.tools.build:gradle:3.2.1'

Option 3: Take into account the following IDE functionalities:

Sync Project with gradle files

Build -> Clean Project

Build -> Rebuild Project

File -> Invalidate caches

answered Mar 25 '19 at 03:12

VIISHRUT MAVANII

11,410
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if you are using Android Studio 3.2.1 then you need to change gradle version with classpath 'com.android.tools.build:gradle:3.2.1' – VIISHRUT MAVANII Mar 25 '19 at 03:14

Android build success but cannot resolve R

1 Answers1