弯曲的导航栏按钮无法正常显示

Question

我正在使用弯曲的导航栏创建一个应用程序，并以此导航应用程序中的其他屏幕。

现在问题区域是，当我在使用弧形导航栏的班级中使用Future Builder时，按钮无法移动。单击底部的五个按钮时，将显示空白屏幕1秒钟，然后导航到实际屏幕，并且当我们单击假定索引为no时，按钮也不会移动。 3。

下面，我在使用curved_navigation_bar的地方共享了我的代码

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:curved_navigation_bar/curved_navigation_bar.dart';
import 'package:flutter_svg/svg.dart';
import 'package:matchstixx/Models/userAccount/userAccount.dart';
import 'package:matchstixx/constants/application.dart';
import 'package:matchstixx/logic/login.dart';
import 'package:matchstixx/styles/colors.dart';

import 'challenges.dart';
import 'create_challenge.dart';
import 'friends_top_navigation.dart';
import 'home_page.dart';
import 'intro_screen.dart';
import 'login_page.dart';

void main() => runApp(MaterialApp(home: BottomNavBar()));

class BottomNavBar extends StatefulWidget {
  @override
  _BottomNavBarState createState() => _BottomNavBarState();
}

class _BottomNavBarState extends State<BottomNavBar> {

  UserAccount userDetails;
  int _indexforNav = 0;
  int loggedIn ;




  Future<void> intiUserModel() async {

    Login loginObject = new Login();
    await loginObject.verifySession().then((data) {
      if(data!=null){
        if (data["sessionStatus"] == SessionType.active) {
          this.userDetails = new UserAccount.fromJson(json.decode(data["userData"]));
          this.loggedIn = SessionType.active;
        } else{
          this.loggedIn = SessionType.expired;
        }
      }else{
        this.loggedIn = SessionType.newUser;
      }
    });
  }

  int _pageIndex = 0;
  GlobalKey _bottomNavigationKey = GlobalKey();



  MyRoute routeList(index){

    List pages;

    pages = [
      MyRoute(
        page: HomePage(this.userDetails),
    ),
    MyRoute(
      page: page2(),
    ),
    MyRoute(
      page: CreateChallenge(this.userDetails),
    ),
    MyRoute(
      page: FriendList(),
    ),
    MyRoute(
      page: Challenges(),
    )
  ];

    return pages[index];
  }

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
          future: intiUserModel(),
          builder: (ctx, snapshot) {
            if (snapshot.connectionState == ConnectionState.done) {

              if(SessionType.active == this.loggedIn){
                return this.makeBottomNav();
              }else if(SessionType.expired == this.loggedIn){
                return LoginPage();
              } else{
                return IntroScreen();
              }
            } else {
              return CircularProgressIndicator();
            }
          });
  }



  Widget makeBottomNav(){
    return SafeArea(
      child: Scaffold(
        bottomNavigationBar: CurvedNavigationBar(
          key: _bottomNavigationKey,
          height: 60,
          animationDuration: Duration(
              milliseconds: 200
          ),
          animationCurve: Curves.easeOut,
          index: 0,
          backgroundColor: bgGray,
          items: <Widget>[
        SvgPicture.asset(
        "assets/bottom-nav-icons/Outline/home.svg",
          height: 30,
          fit: BoxFit.scaleDown,
        ),
          SvgPicture.asset(
            "assets/bottom-nav-icons/Outline/chat.svg",
            height: 30,
            fit: BoxFit.scaleDown,
          ),
          SvgPicture.asset(
            "assets/actions/add.svg",
            height: 30,
            fit: BoxFit.scaleDown,
          ),
          SvgPicture.asset(
            "assets/bottom-nav-icons/Outline/friends.svg",
            height: 30,
            fit: BoxFit.scaleDown,
          ),
          SvgPicture.asset(
            "assets/bottom-nav-icons/Outline/challenges.svg",
            height: 30,
            fit: BoxFit.scaleDown,
          ),
          ],
          onTap: (index) {
            setState(() {
              _pageIndex = index;
            });
          },
        ),
        body: routeList(_pageIndex).page,
      ),
    );

  }

}




class MyRoute {
  final Widget page;

  MyRoute({this.page});
}

class page2 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
        color: bgGray,
        child:Align(
            alignment: Alignment(0, 0),
            child: Text('Under Maintenance',style: TextStyle(fontWeight: FontWeight.bold,fontSize: 25.0),)
        )
    );
  }
}

过去5天来我一直在努力解决此问题，有人可以帮我吗？