我有一个个人API，从那里我可以检索所有需要的信息，连接工作正常，但问题是当我想显示这些值时，我有一个提供程序，我可以将API中所有需要的数据放在那里，我调用它将这些项放在DropDownMenu中，但问题是这些值不显示，即使在数据到达之后，我也知道这一点，这要感谢调试，下面是一些代码：
这是我调用提供程序的小部件的代码：

Column(
                children: [
                  Container(
                    color: Colors.green,
                    child: Row(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          Container(
                            margin: const EdgeInsets.only(top: 20, bottom: 20),
                            height: 10,
                            width: 100,
                            decoration: BoxDecoration(
                                borderRadius: BorderRadius.circular(10),
                                color: Colors.grey),
                          )
                        ]),
                  ),
                  IconList(
                    labelText: 'Landmarks',
                    icon: Icons.panorama_horizontal_outlined,
                    items: context.watch<Landmarks>().getLandmarksNameList(), //Here is my provider
                  ),
                  const IconInput(
                      labelText: '1', icon: Icons.addchart_outlined),
                  const IconInput(
                      labelText: '1', icon: Icons.addchart_outlined),
                  ListView.builder(
                    physics: const NeverScrollableScrollPhysics(),
                    shrinkWrap: true,
                    itemCount: 2,
                    itemBuilder: (BuildContext context, int index) {
                      return UserCard(user: usersList[index]);
                    },
                  ),
                ],
              ),

这是小部件图标列表，其中有下拉菜单：

import 'package:flutter/material.dart';

class IconList extends StatefulWidget {
  final String labelText;
  final IconData icon;
  final List<String> items = [];

  IconList({super.key, required this.labelText, required this.icon, items});

  @override
  State<IconList> createState() => _IconListState();
}

class _IconListState extends State<IconList> {
  @override
  Widget build(BuildContext context) {
    String selectedItem = '';
    if (widget.items.isNotEmpty) {
      selectedItem = widget.items.first;
    }
    return Container(
      margin: const EdgeInsets.all(10.0),
      child: Row(
        children: [
          Icon(widget.icon),
          DropdownButton<String>(
            value: selectedItem,
            items: widget.items.map<DropdownMenuItem<String>>((String value) {
              return DropdownMenuItem<String>(
                value: value,
                child: Text(value),
              );
            }).toList(),
            onChanged: (String? value) {
              setState(() {
                selectedItem = value!;
              });
            },
          ),
        ],
      ),
    );
  }
}

这是我的供应商：

class Landmarks with ChangeNotifier {
  final List<Landmark> _items = [];

  List<Landmark> get landmarks => _items;

  void addLandmarks(List<Landmark> value) {
    _items.addAll(value);
    notifyListeners();
  }

  List<String> getLandmarksNameList() {
    List<String> list = [];
    print(_items.length);
    for (int i = 0; i < _items.length; i++) {
      list.add(_items[i].name);
    }
    return list;
  }
}