Flutter -如何设置AppBar标题高度

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: PreferredSize(
            preferredSize: Size.fromHeight(50.0), // 设置标题高度
            child: Text(
              'Custom AppBar Title',
              style: TextStyle(fontSize: 20.0),
            ),
          ),
        ),
        body: Center(
          child: Text('Hello, Flutter!'),
        ),
      ),
    );
  }
}