Flutter：第一次读取文件失败，但在热重载后工作

我尝试读取存储数据的文件并将其显示在我的屏幕上。当我第一次加载我的应用程序时，我收到如下所示的错误。热重新加载后，我的信息将显示没有任何错误。您知道为什么会发生这种情况以及如何确保我的数据在第一时间就已经加载了吗？

也许这与打电话给国家有关，但我不知道。这是导致问题的底部代码：

孩子：文本（context.select（（FileController控制器）=>控制器。文本！）），

import 'package:flutter/material.dart';
import 'package:habit_changer/file-handling/file_controller.dart';
import 'package:habit_changer/main/AddHabitDialog.dart';
import 'package:provider/provider.dart';
import '../utils/Constants.dart';
import 'MainBody.dart';
import 'nav_bar.dart';

void main() {
  runApp(MultiProvider(
    providers: [ChangeNotifierProvider(create: (_) => FileController())],
    child: MaterialApp(home: MyApp())
  ));
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    context.read<FileController>().readText();
    return Scaffold(
      appBar: AppBar(
        title: const Text('Habits'),
        backgroundColor: Constants.appBarColor,
        leading: GestureDetector(
          onTap: () {
            openNavBar();
          },
          child: Icon(
            Icons.menu, // add custom icons also
          ),
        ),
        actions: <Widget>[
          Padding(
            padding: EdgeInsets.only(right: 20.0),
            child: GestureDetector(
              onTap: () {
                showDialog(
                  context: context,
                  builder: (BuildContext context) =>
                      AddHabitDialog().buildPopupDialog(context),
                );
              },
              child: Icon(Icons.add),
            ),
          )
        ],
      ),
      body: Container(
        child: Text(context.select((FileController controller) => controller.text!)),
      ),
    );
  }
}

这是错误：

Null check operator used on a null value

The relevant error-causing widget was: 
  MyApp file:///C:/Projekte/Flutter%20Projects/habit_changer/lib/main/main.dart:13:30
When the exception was thrown, this was the stack: 
#0      MyApp.build.<anonymous closure> (package:habit_changer/main/main.dart:52:82)
#1      SelectContext.select (package:provider/src/inherited_provider.dart:283:32)
#2      MyApp.build (package:habit_changer/main/main.dart:52:29)
#3      StatelessElement.build (package:flutter/src/widgets/framework.dart:4648:28)
#4      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4574:15)