A few points to start working on Android Studio

Import Github project error

When download and import Github project into Android Studio, encountered error ​​"Plugin with id 'com.android.application' not found"​​​, there should be two ​​build.gradle​​​ file in the project, the project ​​build.gradle​​​ file and module ​​build.gradle​​​ file. Somehow after importing into the Android Studio, the content of project ​​build.gradle​​​ file becomes the same as module ​​build.gradle​​ file, after building, it returns error `“Plugin with id ‘com.android.application’ not found”.

Solution:
Refer to
​​​Android Studio导入工程报错[Plugin with id ‘com.android.application’ not found]​​​​解决错误：Plugin with id ‘com.android.application’ not found​​​​Android Gradle plugin release notes​​

Solution 1:
Copy the correct plug-in content into project ​​​build.gradle​​ file, below is an example:

// 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:3.1.3'

        classpath 'io.realm:realm-gradle-plugin:5.3.0'

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

Solution 2:
Go to ​​​File > Project Structure > Project menu in Android Studio​​ to set the correct Android plug-in version.

Configure on-device developer options

Refer to below links:
​​​Configure on-device developer options​​​​Configure Android Studio​​​​Run apps on a hardware device​​​​3.1: The Android Studio Debugger​​

can’t have non-Gradle Java modules and Android-Gradle modules in one project

Solution:
Refer to
​​​Error: Unfortunately you can’t have non-Gradle Java modules and > Android-Gradle modules in one project​​

1- close the project

2- close Android Studio IDE

3- delete the .idea directory

4- delete all .iml files

5-

Setting the ConstraintLayout

Refer to ​​How to center the elements in ConstraintLayout​​

app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"

Reference

​​Android Studio导入工程报错[Plugin with id ‘com.android.application’ not found]​​​​解决错误：Plugin with id ‘com.android.application’ not found​​​​Android Gradle plugin release notes​​​​Configure on-device developer options​​​​Configure Android Studio​​​​Run apps on a hardware device​​​​3.1: The Android Studio Debugger​​​​Error: Unfortunately you can’t have non-Gradle Java modules and > Android-Gradle modules in one project​​​​How to center the elements in ConstraintLayout​​