在AppBar和TabBarView下设置标高

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          elevation: 4, // 设置AppBar的标高为4
          title: Text('AppBar with Elevation'),
        ),
        body: DefaultTabController(
          length: 3,
          child: Scaffold(
            appBar: AppBar(
              elevation: 2, // 设置TabBarView的标高为2
              bottom: TabBar(
                tabs: [
                  Tab(icon: Icon(Icons.home)),
                  Tab(icon: Icon(Icons.favorite)),
                  Tab(icon: Icon(Icons.settings)),
                ],
              ),
            ),
            body: TabBarView(
              children: [
                Center(child: Text('Home')),
                Center(child: Text('Favorite')),
                Center(child: Text('Settings')),
              ],
            ),
          ),
        ),
      ),
    );
  }
}