在Flutter中添加自定义字体时，FontWeight不会影响文本

flutter:
  fonts:
    - family: CustomFont
      fonts:
        - asset: assets/fonts/CustomFont.ttf
          weight: 400
        - asset: assets/fonts/CustomFontBold.ttf
          weight: 700

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Custom Font Example',
      theme: ThemeData(
        textTheme: TextTheme(
          bodyText1: TextStyle(
            fontFamily: 'CustomFont',
            fontWeight: FontWeight.normal,
            fontSize: 16,
          ),
          bodyText2: TextStyle(
            fontFamily: 'CustomFont',
            fontWeight: FontWeight.bold,
            fontSize: 16,
          ),
        ),
      ),
      home: Scaffold(
        appBar: AppBar(
          title: Text('Custom Font Example'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text('Normal Text', style: Theme.of(context).textTheme.bodyText1),
              Text('Bold Text', style: Theme.of(context).textTheme.bodyText2),
            ],
          ),
        ),
      ),
    );
  }
}