使用wifi_iot 0.3.18写一个flutter弹出WIFI选择连接的页面，并返回给调用页面的demo.

好的，下面是一个完整的示例代码，可以弹出Wi-Fi选择页面并返回所选网络的SSID：

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

class WifiSelectionPage extends StatefulWidget {
  @override
  _WifiSelectionPageState createState() => _WifiSelectionPageState();
}

class _WifiSelectionPageState extends State<WifiSelectionPage> {
  List<WifiNetwork> _wifiNetworks = [];

  @override
  void initState() {
    super.initState();
    _getWifiNetworks();
  }

  Future<void> _getWifiNetworks() async {
    List<WifiNetwork> wifiNetworks = await WifiWizard.listWifiNetworks();
    setState(() {
      _wifiNetworks = wifiNetworks;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Select a Wi-Fi Network'),
      ),
      body: ListView.builder(
        itemCount: _wifiNetworks.length,
        itemBuilder: (BuildContext context, int index) {
          return ListTile(
            title: Text(_wifiNetworks[index].ssid),
            onTap: () {
              Navigator.pop(context, _wifiNetworks[index].ssid);
            },
          );
        },
      ),
    );
  }
}

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  String _selectedWifiNetwork = '';

  Future<void> _selectWifiNetwork() async {
    String wifiNetwork = await Navigator.push(
      context,
      MaterialPageRoute(builder: (context) => WifiSelectionPage()),
    );
    setState(() {
      _selectedWifiNetwork = wifiNetwork;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Wi-Fi Selection Demo'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text('Selected Wi-Fi Network:'),
            SizedBox(height: 20),
            Text(
              _selectedWifiNetwork,
              style: TextStyle(fontSize: 20),
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _selectWifiNetwork,
        child: Icon(Icons.wifi),
      ),
    );
  }
}

在这个示例中，我们创建了两个页面：`HomePage`和`WifiSelectionPage`。`HomePage`显示一个浮动操作按钮，点击它可以弹出`WifiSelectionPage`来选择一个Wi-Fi网络。`WifiSelectionPage`列出所有可用的Wi-Fi网络，并允许用户选择一个网络，然后返回所选网络的SSID。

希望这可以帮助你实现你的需求。