androidandroid-support-libraryandroid-appcompatandroid-library

Reputation: 2420

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

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.

Upvotes: 92

Answers (28)

thundernhut

Reputation: 11

Mainly, you are facing the strange problem with import android.support.v7.app.*; You should make these replacements: in all your files, never use AppCompatActivity, use Activity instead; If you have to use ActivityCompat and Activity class, you must use these import:

import androidx.appcompat.app.AlertDialog;
import androidx.core.app.ActivityCompat;
import android.app.Activity;

In build.gradle : remove all 3 lines:

 implementation 'com.android.support:appcompat-v7:28.0.0'
 implementation "com.android.support:support-v4:28.0.0"
 implementation "com.android.support:support-v13:28.0.0"

Fix versions of these lib like this: (you can try other numbers)

implementation 'androidx.constraintlayout:constraintlayout:1.1.1'
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'com.google.android.material:material:1.1.0'

In gradle.properties :

android.useAndroidX=true
android.enableJetifier=true

You should use the same build tool and gradle wrapper version like me. in build.gradle :

classpath 'com.android.tools.build:gradle:3.3.0'

in gradle-wrapper.properties :

distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.1-all.zip

Gradle JDK: I use version JDK 11. [1]: https://i.sstatic.net/v8UGIMIo.png

Upvotes: 0

AgungCode.Com

Reputation: 787

Support V7 AppCompat requires compatible Gradle Version as below,

its work for me

Upvotes: 1

MN7272

Reputation: 19

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'

Upvotes: 0

Pulkit Ahuja

Reputation: 51

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

this resolved my issue

Upvotes: 2

Bhaskar Mandavilli

Reputation: 11

After invalidating Cache, changing from

import android.support.v7.app.AppCompatActivity;

import androidx.appcompat.app.AppCompatActivity;

worked for me.

Upvotes: 1

cmcodes

Reputation: 1866

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;

Upvotes: 0

Preet Govind

Reputation: 71

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="...."

Upvotes: 0

Dheeraj Pramod Naik

Reputation: 51

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.

Upvotes: 5

Ismael Nadaf

Reputation: 31

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

import android.support.v7.app.AppCompatActivity;

To:

import androidx.appcompat.app.AppCompatActivity;

Upvotes: 3

Deepali Maniyar

Reputation: 149

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.

Upvotes: 3

user1078632

Reputation: 51

Replace the

import android.support.v7.app.AppCompatActivity;

with import androidx.appcompat.app.AppCompatActivity

Upvotes: 5

HeshanHH

Reputation: 703

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.

Upvotes: 2

Imran S M

Reputation: 525

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'

Upvotes: 6

Ave Maria

Reputation: 81

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.

Upvotes: 1

anoja madusanka

Reputation: 149

File->Invalidate Caches/Restart works for me.

Upvotes: 2

Mina chen

Reputation: 1684

If you use androidX instead of android, you need change

import android.support.v7.app.AppCompatActivity;

import androidx.appcompat.app.AppCompatActivity;

and change

<android.support.constraint.ConstraintLayout>

<androidx.constraintlayout.widget.ConstraintLayout>

Upvotes: 77

Jeril Kuruvila

Reputation: 19960

If you have already tried

Invalidating caches and restarting
Cleaning/rebuilding the project
./gradlew clean assemble
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"
Corrected import to android.support.v7.app.AppCompatActivity;
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"

Upvotes: 12

Richard Strand

Reputation: 743

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"

Upvotes: 22

airvine

Reputation: 721

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.

Upvotes: 3

catweazle

Reputation: 47

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.