异步任务完成后删除启动画面

Question

我正在尝试创建一个初始屏幕，并且在加载初始屏幕时，我想从本地存储中加载用户的首选项并获取用户的地理位置。

我该怎么做？下面是我尝试过的示例代码。

下面是我的 main.dart 文件。

<%= form_with scope: :article, url: articles_path, local: true do |form| %>

  <% if @article.errors.any? %>
    <div id='error_explanation'>
      <h2>
        <%= pluralize(@article.errors.count, "error") %> prohibited this articles from being saved:
      </h2>
      <ul>
        <% @article.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
        <% end %>
      </ul>
    </div>
  <% end %>

  <p>
    <%= form.label :title %><br>
    <%= form.text_field :title %>
  </p>

  <p>
    <%= form.label :text %><br>
    <%= form.text_area :text %>
  </p>

    <p>
      <%= form.submit %>
<% end %>

<%= link_to 'Back', articles_path %>

下面是我的 global.dart 文件。

import 'package:flutter/material.dart';
import 'package:my_products/page/home.dart';
import "./component/choice.dart";
import "global.dart";

void main(){
    runApp(
        new MaterialApp(
            home: SplashScreen(),
            debugShowCheckedModeBanner: false,
            debugShowMaterialGrid: false,
        )
    );
}
class SplashScreen extends StatefulWidget {

    @override
    State<StatefulWidget> createState() {
        return SplashScreenState();
    }
}

class SplashScreenState extends State<SplashScreen> with SingleTickerProviderStateMixin{
    bool loaded = false;
    AnimationController _animationController;
    Animation _animation;

    getUserLangPref(){
        String language;
//      print(identical(Global(), Global()));
//      print(Global().location);
//      Global().prefStorage.ready.then((_){
            language = Global().language;
            loaded = (language != null) ? true : false;
            Future.delayed(const Duration(milliseconds: 2000), ()=> afterPrefLoaded());
//      });
    }


    @override
    void initState() {
        super.initState();
        _animationController = new AnimationController(
            vsync: this, duration: Duration(milliseconds: 800));
        _animation = Tween(begin: 0.0, end: 1.0).animate(CurvedAnimation(
            parent: _animationController, curve: Curves.easeInCirc));
        _animationController.forward();
        Future.wait([Global().ready]);
        print("======");
        print(Global().location);
        print("======");
        Global().ready.then((_) => getUserLangPref());
        Global().ready.then((_) => print(Global().location));
        print("======");
    }

    afterPrefLoaded() async {
        if (loaded) {
            Navigator.of(context).pushReplacement(
                MaterialPageRoute(builder: (context) => MyHome()));
        } else {
            Navigator.of(context).pushReplacement(
                MaterialPageRoute(builder: (context) => LanguageChoice()));
        }
    }

    @override
    Widget build(BuildContext context) {
        return Scaffold(
            backgroundColor: Colors.white,
            body: FadeTransition(
                opacity: _animation,
                child: Center(
                    child:
                    SizedBox(height: 250.0, child: Image.asset('images/my.jpg')))));
    }
}