flutter:如何在页面前面添加一个加载(ios风格)？

bool isLoading = true;

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

class MyPage extends StatefulWidget {
  @override
  _MyPageState createState() => _MyPageState();
}

class _MyPageState extends State<MyPage> {
  bool isLoading = true;

  @override
  void initState() {
    super.initState();
    // 模拟加载延迟
    Future.delayed(Duration(seconds: 2), () {
      setState(() {
        isLoading = false;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My Page'),
      ),
      body: Stack(
        children: [
          // 页面内容
          Center(
            child: Text('Page Content'),
          ),
          // 加载指示器
          if (isLoading)
            Container(
              color: Colors.black45,
              child: Center(
                child: CupertinoActivityIndicator(),
              ),
            ),
        ],
      ),
    );
  }
}