Flutter 如何从模型列表中生成DropdownButtonFormField

我在运行以下代码时遇到了一个错误:

_TypeError (type 'List<dynamic>' is not a subtype of type 'List<DropdownMenuItem<int>>?')

 Widget getDropDownMenu() {
return FutureBuilder(
    future: getOptionList(),
    builder: (BuildContext context, AsyncSnapshot snapshot) {
      if (snapshot.connectionState == ConnectionState.waiting) {
        // While the task is happening, show a loading spinner
        return Center(
          child: CircularProgressIndicator(),
        );
      } else if (snapshot.hasError) {
        // If there's an error, display an error message
        return Center(
          child: Text('Error: ${snapshot.error}'),
        );
      } else {
        return DropdownButtonFormField(
          validator: (value) {
            if (value == 0) {
              return 'Please choose an option from the list';
            }
            return null;
          },
     
          decoration: InputDecoration(
            border:
                OutlineInputBorder(borderRadius: BorderRadius.circular(10)),
          ),
          value: _indicators_field_value,
          items: snapshot.data.map((map) {
            return DropdownMenuItem(
              child: Text(map.name),
              value: map.id,
            );
          }).toList(),
          onChanged: (v) {
            this._indicators_field_value = v!;
          },
        );
      }
    });

}

getOptionList()将从API获取数据并放入模型中. 我从调用这个函数得到的是一个Model列表.List<Model>

我试了好几个小时才决定在这里问.