尝试添加原色时，Flutter ThemeData 原色不会与主题发生变化

Question

我在 LinkedIn Learning 上关注来自 London App Brewery 的 BMI Calculator 应用程序。
尝试将primaryColor设置为红色时，即使我覆盖了Primary Color，我的模拟器仍然显示Light Blue默认AppBar。这是代码

    import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primaryColor: Colors.red,
      ),
      home: const InputPage(),
    );
  }
}

class InputPage extends StatefulWidget {
  const InputPage({Key? key}) : super(key: key);

  @override
  _InputPageState createState() => _InputPageState();
}

class _InputPageState extends State<InputPage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('BMI CALCULATOR'),
      ),
      body: const Center(
        child: Text('Body Text'),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {},
        child: const Icon(Icons.add),
      ),
    );
  }
}

Answer 1

使用主色板

theme: ThemeData(
    primarySwatch: Colors.red,
  ),