对于Flutter项目，之前如果创建是不支持AndroidX的，怎么快速适配AndroidX呢？
其实很简单：
1、在/android/gradle.properties文件里面，添加两个配置

android.useAndroidX=true
android.enableJetifier=true

2、然后在将android里面support的包文件用androidx的包文件替代，下面以MainActivity为例:

package com.example.aethersharedcommunication;

import android.os.Bundle;

import org.devio.flutter.splashscreen.SplashScreen;
//导入AndroidX的包文件
import androidx.annotation.NonNull;
//这个是AndroidX之前android用的包文件
//import android.support.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugins.GeneratedPluginRegistrant;

public class MainActivity extends FlutterActivity {
  @Override
  public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
    GeneratedPluginRegistrant.registerWith(flutterEngine);
  }
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    SplashScreen.show(this, true);
    super.onCreate(savedInstanceState);
  }
}