How do i fix this error of 'simple_permissions' on flutter?

Question

There is an error when I run the code including simple_permissions on flutter project.

Initializing gradle...
Resolving dependencies...
Running Gradle task 'assembleDebug'...
C:\Users\ria\Downloads\flutter_windows_v1.2.1-stable\flutter\.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:9: error: cannot find symbol
import android.support.v4.app.ActivityCompat;
                             ^
  symbol:   class ActivityCompat
  location: package android.support.v4.app
C:\Users\ria\Downloads\flutter_windows_v1.2.1-stable\flutter\.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:10: error: package android.support.v4.content does not exist
import android.support.v4.content.ContextCompat;
                                 ^
C:\Users\ria\Downloads\flutter_windows_v1.2.1-stable\flutter\.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:156: error: cannot find symbol
        ActivityCompat.requestPermissions(activity, perm, 0);
        ^
  symbol:   variable ActivityCompat
  location: class SimplePermissionsPlugin
C:\Users\ria\Downloads\flutter_windows_v1.2.1-stable\flutter\.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:163: error: cannot find symbol
        return PackageManager.PERMISSION_GRANTED == ContextCompat.checkSelfPermission(activity, permission);
                                                    ^
  symbol:   variable ContextCompat
  location: class SimplePermissionsPlugin
C:\Users\ria\Downloads\flutter_windows_v1.2.1-stable\flutter\.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:171: error: cannot find symbol
            if (ActivityCompat.shouldShowRequestPermissionRationale(registrar.activity(), permission)) {
                ^
  symbol:   variable ActivityCompat
  location: class SimplePermissionsPlugin
C:\Users\ria\Downloads\flutter_windows_v1.2.1-stable\flutter\.pub-cache\hosted\pub.dartlang.org\simple_permissions-0.1.9\android\src\main\java\com\ethras\simplepermissions\SimplePermissionsPlugin.java:175: error: cannot find symbol
                if (ActivityCompat.checkSelfPermission(registrar.context(), permission) == PackageManager.PERMISSION_GRANTED) {
                    ^
  symbol:   variable ActivityCompat
  location: class SimplePermissionsPlugin
6 errors

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':simple_permissions:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 2s
Finished with error: Gradle task assembleDebug failed with exit code 1
*******************************************************************************************
The Gradle failure may have been because of AndroidX incompatibilities in this Flutter app.

*******************************************************************************************

Solution

I was getting the same issue, after some searches I found this repository.

https://github.com/tq-systems/simple_permissions

This repository solved the AndroidX compatibility issues. import it into the pubspec.yaml like that:

dependencies:
  simple_permissions:
    git:
      url: https://github.com/tq-systems/simple_permissions.git