Why this android project is not recognizing AppCompatActivity?-CodePudding

I am new to android programming and trying to build this android project in udacity's basic android course. But after updating to latest android studio bumblebee version, its starting to throws these errors:

Cannot resolve symbol 'v7'
Cannot resolve symbol 'AppCompatActivity'.

The import statement is grayed out.

import android.support.v7.app.AppCompatActivity;

My build.gradle is

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25

    defaultConfig {
        applicationId "com.example.android.explicitintent"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:25.4.0'

}

I have tried the following, but still it doesn't work:

Clean Project
Restart and Invalidated cache
Deleted .idea folder and reopened project

But nothing seems to work so far. Your help will be highly appreciated.

CodePudding user response：

Migrate your project to androidx Steps to do so :- Refactor>Migrate to Androidx it will download the necessary files your error should be gone !!