Cannot resolve symbol AppCompatActivity - Support v7 libraries aren't recognized?

Question

I'm trying to figure out why the heck my Android studio isn't recognizing the AppCompat v7 library correctly. The import statement below shows up as gray and says there's no package for support.v7.app. Below is my activity file:

import android.support.v7.app.AppCompatActivity;


public class XApplicationActivity extends AppCompatActivity

My build.grade:

compile "com.android.support:appcompat-v7:22.0.0"
compile "com.android.support:support-annotations:$ANDROID_SUPPORT_VERSION"
compile "com.android.support:support-v4:$ANDROID_SUPPORT_VERSION"

My project settings:

minSdkVersion = 14
targetSdkVersion = 21
compileSdkVersion = 21
buildToolsVersion = "22.0.1"

So I'm really confused as to why this is still giving me issues. Things I've tried already:

• Cleaning/rebuilding the project
• Invalidating caches and restarting
• Checking a billion times to make sure I have the support library installed (I absolutely do have the latest support repository and libraries installed)

Anybody know of any fixes? It's cost me a lot of time and it's really frustrating.

Answer 1

Okay, I fixed it by rebuilding it for doing a ./gradlew clean assemble for the fourth time... Android Studio is a weird thing

Answer 2

AppCompatActivity was only added in version 22.1.0 of the support library. Before that it was called ActionBarActivity.

You should use the same version for all of your support libraries. At the time of writing the latest version is 23.1.1 (you can find out the latest here https://developer.android.com/tools/support-library/index.html#revisions) so the dependencies section of your gradle file should look like this.

implementation "com.android.support:support-v4:23.1.1"
implementation "com.android.support:appcompat-v7:23.1.1"
implementation "com.android.support:support-annotations:23.1.1"

Answer 3

For me, Even after upgrading to appcompat-v7:22.1.0, in which AppCompatActivty is added, the problem was not resolved for me, Android Studio was giving same problem

Cannot resolve symbol 'AppCompatActivity'

Sometimes clearing the android studio caches help.

In android studio I just cleared the caches and restarted with the following option--

File->Invalidate Caches/Restart

Answer 4

After invalidating Cache, changing from

import android.support.v7.app.AppCompatActivity;

to

import androidx.appcompat.app.AppCompatActivity;

worked for me.

Answer 5

I changed from "... extends ActionBarActivity" to "... extends AppCompatActivity" and tried cleaning, restarting, Invalidate Caches / Restart and wasn't getting anywhere. All my versions were up to the latest.

What finally solved it was making sure my import was correct:

import android.support.v7.app.AppCompatActivity;

For some reason it didn't get set up automatically like I was used to and I had to add it manually.

Hope that helps someone!

Answer 6

1.Delete the .idea folder
2.Close and reopen the project
3.File - > Sync Project With Gradle Files

This worked for me

Answer 7

Background info:

My IDE

Android Studio 3.1.3
Build #AI-173.4819257, built on June 4, 2018
JRE: 1.8.0_152-release-1024-b02 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 7 6.1

First solution: Import the project again and don't agree to upgrade the android gradle plug-in.

Second solution: Your files should contain these fragments.

build.gradle:

buildscript {
  repositories {
    jcenter()
    google()//this is important for gradle 4.1 and above
  }
  dependencies {
    classpath 'com.android.tools.build:gradle:3.1.3' //this android plugin for gradle requires gradle version 4.4 and above
  }
}
allprojects {
  //...
  repositories {
    jcenter()
    google()//This was not added by update IDE-wizard-button.
    //I need this when using the latest com.android.support:appcompat-v7:25.4.0 in app/build.gradle
  }
}

Either follow the recommendation of your IDE to upgrade your gradle version to 4.4 or consider to have this in gradle/wrapper/gradle-wrapper.properties

distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip

Optional change buildToolsVersion in app/build.gradle:

android {
compileSdkVersion 25
buildToolsVersion '27.0.3'

app/build.gradle: comment out the dependencies and let the build fail (automatically or trigger it)

dependencies {
//compile fileTree(dir: 'libs', include: ['*.jar'])
//compile 'com.android.support:appcompat-v7:25.1.0'
}

app/build.gradle: comment in the dependencies again. It's been advised to change them from compile to implementation, but for now it's just a warning issue.

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:25.1.0'
}

After project rebuilding, the import statement shouldn't be greyed-out anymore; try to invoke Ctrl+h on the class. But for some reason, the error markers on those class-referencing-statements are still present. To get rid of them, we need to hide and restore the project tree view or alternatively close and reopen the project.

Finally that's it.

Further Readings:

Update Gradle

Use the new dependency configurations

If you prefer a picture trail for my solution, you can visit my blog

Answer 8

I went through the same situation and the fix was quiet easy. Just try removing the following import statement.

import android.support.v7.app.AppCompatActivity;

A message will be prompted with the below code, also asking you to press alt+enter.

import androidx.appcompat.app.AppCompatActivity;

Just press alt+enter and remove the previous import statement completely.

Basically this problem arises in new version of Android Studio.

Answer 9

I had these settings in 'gradle.properties'

android.useAndroidX=true # Automatically convert third-party libraries to use AndroidX android.enableJetifier=true

It is better to use androidx library. So I changed all imports to androidx library and project compiled. visit http://developer.android.com/jetpack/androidx for information.

Answer 10

Replace the

import android.support.v7.app.AppCompatActivity;

with import androidx.appcompat.app.AppCompatActivity

Answer 11

I got the same exact error with In case it helps others .. documenting what worked for me useful for very latest (Jan 14, 2017) latest everything. Tried all the Invalidate, build clean, even deleting .gradle/, tweaking the support libs etc.. on multiple stack overflow answers.

I found that upgrading the settings.gradle gradle version fixed it (it was 2.1.3) something in gradle toolchain seems to classpath 'com.android.tools.build:gradle:2.2.3'

Answer 12

If the given solutions does not work, create a new project with 'KOTLIN' as the language even if your work is on java. Then replace the 'main' folder of the new project with the 'main' folder of the old.

Answer 13

I had the same problem in my newly started project with minimum api 23, and finally i have added these lines of codes in my gradle dependency file and it solved the error:)

 implementation 'com.android.support:appcompat-v7:28.0.0'
 implementation 'com.android.support:customtabs:28.0.0'
 implementation 'com.android.support:support-vector-drawable:28.0.0'
 implementation 'com.android.support:support-media-compat:28.0.0'

Answer 14

Support V7 AppCompat requires compatible Gradle Version as below,

its work for me

Answer 15

Follow these steps:

File >> Invalidate Caches / Restart
Clean project
Finally go to build.gradle
And compileSdkVersion and targetSdkVersion lower version
If 
implementation 'com.android.support:appcompat-v7:29.0.0'
Convert this to 
implementation 'com.android.support:appcompat-v7:28.0.0'

Answer 16

The best solution is definitely to go to File>Invalidate Caches & Restart

Then in the dialog menu... Click Invalidate Caches & Restart. Wait a minute or however long it takes to reset your project, then you should be good.

--

I should note that I also ran into the issue of referencing a resource file or "R" file that was inside a compileOnly library that I had inside my gradle. (i.e. compileOnly library > res > referenced xml file) I stopped referencing this file in my Java code and it helped me. So be weary of where you are referencing files.

Answer 17

We don´t need to delete files, just invalidate caches to restart configuration:

Answer 18

If you have already tried

1. Invalidating caches and restarting
2. Cleaning/rebuilding the project
3. ./gradlew clean assemble
4. added implementation
   "com.android.support:support-v4:23.1.1"
   "com.android.support:appcompat-v7:23.1.1"
   "com.android.support:support-annotations:23.1.1"
5. Corrected import to android.support.v7.app.AppCompatActivity;
6. Corrected any existing androidx imports

Still facing issue then please read below

Finally found the solution

I tried everything mentioned in all the answers and failed.

Go to gradle.properties make these flags false

android.useAndroidX=false

//Automatically convert third-party libraries to use AndroidX

android.enableJetifier=false

The above flags were

"true ,for me and hence gradle won't download v7 components"

Answer 19

Delete .idea folder in your project which is hidden folder. Goto your project in the system and Click ctrl+H it will be visible then delete it. Now restart your android studio.I will resolve. Its working for me.

Answer 20

For me, the below code worked well:

import android.os.Bundle;

import androidx.appcompat.app.AppCompatActivity;

With the (xml file):

androidx.constraintlayout.widget.ConstraintLayout xmlns:android="...."

Answer 21

The issue could be import reference,
try changing it. From:

import android.support.v7.app.AppCompatActivity;

To:

import androidx.appcompat.app.AppCompatActivity;

Answer 22

Include import androidx.appcompat.app.AppCompatActivity; in your MainActivity.java with other import statements. This would look like:

this resolved my issue

Answer 23

androidX users

Change your minSdkVersion to api level 21.

like this minSdkVersion 21 or build your app with compileSdkVersion 28 and also change targetSdkVersion to targetSdkVersion 28

and you will see v7 error will gone. After that if you face a problem with creating Toolbar or other widget. press Alt+Enter and create a method for it.

Answer 24

File->Invalidate Caches/Restart works for me.

Answer 25

I just commented it and used androidx and now it's working all good!

import androidx.appcompat.app.AppCompatActivity;
// import android.support.v7.app.AppCompatActivity;

Answer 26

The solution I followed is summarized in the below steps:

1. From Build menu, select Edit Libraries and Dependancies

2. Make sure you add the latest AppCompat package if not added

3. After adding it, clean your project and rebuild it.

Answer 27

If you use androidX instead of android, you need change

import android.support.v7.app.AppCompatActivity;

to

import androidx.appcompat.app.AppCompatActivity;

and change

<android.support.constraint.ConstraintLayout>

to

<androidx.constraintlayout.widget.ConstraintLayout>