尝试将模型传递给视图但出现异常[重复]

Question

我的问题

我是新人，我需要一些帮助，但以下例外。我反序列化一个 JSON 数组，并根据我所做的所有阅读，我相信我正在将模型传递给视图。

阅读异常，我可以推断出 models.Rootobject 和 models.Survey 之间存在某种不匹配。

我尝试将 Rootboject 转换为 List，但这会生成不同的异常，我认为这可以解决 IEnumerable 问题。

所以我认为我有两个问题，我认为模型由于某种原因不匹配，而且视图需要一个列表，而我没有提供列表。值得注意的是，我从模型自动生成了视图。

An unhandled exception occurred while processing the request.
InvalidOperationException: The model item passed into the ViewDataDictionary 
is of type 'AgeCareTech.Models.Rootobject', but this ViewDataDictionary 
instance requires a model item of type 
'System.Collections.Generic.IEnumerable`1[AgeCareTech.Models.Survey]'.

型号

namespace AgeCareTech.Models
{
public class Rootobject
{
    [JsonProperty("surveys")]
    public Survey[] surveys { get; set; }
}

public class Survey
{
    [JsonProperty("survey_id")]
    public int survey_id { get; set; }

    [JsonProperty("title")]
    public string title { get; set; }

    [JsonProperty("created_on")]
    public DateTime created_on { get; set; }

    [JsonProperty("number_of_questions")]
    public int number_of_questions { get; set; }

    [JsonProperty("number_of_responses")]
    public int number_of_responses { get; set; }
}

}

查看

@model IEnumerable<AgeCareTech.Models.Survey>

@{
    ViewData["Title"] = "Index";
}

<h2>Index</h2>

<p>
    <a asp-action="Create">Create New</a>
</p>
<table class="table">
    <thead>
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.title)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.created_on)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.number_of_questions)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.number_of_responses)
            </th>
            <th></th>
        </tr>
    </thead>
    <tbody>
@foreach (var item in Model) {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.title)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.created_on)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.number_of_questions)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.number_of_responses)
            </td>
            <td>
                <a asp-action="Edit" asp-route-id="@item.survey_id">Edit</a> |
                <a asp-action="Details" asp-route-id="@item.survey_id">Details</a> |
                <a asp-action="Delete" asp-route-id="@item.survey_id">Delete</a>
            </td>
        </tr>
}
    </tbody>
</table>

控制器

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using System.Net.Http;
using System.Net.Http.Headers;
using AgeCareTech.Models;

namespace AgeCareTech.Controllers
{
    public class SurveyHeroSurveyController : Controller
    {
        public async Task<IActionResult> Index()
        {
            string uri = "http://www.mocky.io/v2/5bcb430c2f0000730075beb1";

            Rootobject SurveyHeroInfo = new Rootobject();

            using (HttpClient SurveyHeroAPI = new HttpClient())
            {
                SurveyHeroAPI.BaseAddress = new Uri(uri);
                SurveyHeroAPI.DefaultRequestHeaders.Clear();
                SurveyHeroAPI.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                HttpResponseMessage Response = await SurveyHeroAPI.GetAsync(uri, HttpCompletionOption.ResponseContentRead);

                if (Response.IsSuccessStatusCode)
                {
                    var SurveyHeroResponse = Response.Content.ReadAsStringAsync().Result;

                    SurveyHeroInfo = JsonConvert.DeserializeObject<Rootobject>(SurveyHeroResponse);
                }
            }

            return View(SurveyHeroInfo);
        }
    }
}

Answer 1

您说出您的期望：

@model IEnumerable<AgeCareTech.Models.Survey>

...但是你给它一个

Rootobject

对象。

Rootobject

不是

IEnumerable<Survey>

。错误信息很清楚并且非常正确。尝试告诉你的观点期待

Rootobject

:

@model Rootobject

Answer 2

消息很明确 - 视图需要

IEnumerable<AgeCareTech.Models.Survey>

类型的模型，但您正在发送

AgeCareTech.Models.Rootobject

。所以，而不是

return View(SurveyHeroInfo);

尝试

return View(SurveyHeroInfo.surveys);    

或者，作为替代方案，按照@kaffekopp 的建议更改视图模型