控制器无法读取从 MVC 中的视图返回的模型

Question

我在我的项目中使用 MVC 框架并使用模型绑定来填充视图，然后使用两个控制器从视图中检索值。

我可以用模型属性填充视图，但是当我尝试通过单击提交按钮检索值时。模型 returns 空属性。

这是视图模型：

public partial class QuestionAnswer
{
    public string QuestionText { get; set; }
    public string QuestionId { get; set; }
    public string AnswerText { get; set; }
    public string SectionName { get; set; }
    public bool IsChecked { get; set; }
}
public partial class pluralQuestionAnswer
{
    public Dictionary<int, QuestionAnswer> QnAs { get; set; }
    public Dictionary<string, int> SectionNameWithRank { get; set; }
    public Dictionary<string, int> SectionNameWithQuestionCount { get; set; }
}

控制器如下：

namespace Temp.Controllers
    {
        public partial class AIPController : Controller
        {
            public ActionResult FirstInitiative()
            {
                pluralQuestionAnswer ViewModel = new pluralQuestionAnswer();
                //code to fill the model ViewModel
                return View(ViewModel);
            }

            [HttpPost]
            public ActionResult SaveSelectedInitiatives(pluralQuestionAnswer ViewModel, string Save)
            {
                //some code that uses ViewModel
                //this is where ViewModel shows all properties as null
                return View();
            }
        }
    }

FirstInitiative 用于通过传递 viewModel 生成视图，SaveSelectedInitiatives 用于从视图检索的 viewModel 中获取值。

视图如下：

@using Models;
@model pluralQuestionAnswer

@{
    ViewBag.Title = "FirstInitiative";
    int sectionIterator;
    int sectionPracticeIterator;
    int totalPracticeIterator = 1;
}

<header></header>

<section>

    <header>
        <h1>First Initiative</h1>
    </header>

    @using (Html.BeginForm("SaveSelectedInitiatives", "AIP", FormMethod.Post))
    {
        <div class="inititive-table" style="overflow:auto">
            <div class="inititive-table-header">
                <div class="initiative-questioncolumn">
                    Common Minimum Practices
                </div>
                <div class="initiative-answercolumn">
                    Your response
                </div>
            </div>
            @for (sectionIterator = 1; sectionIterator <= Model.SectionNameWithRank.Count; sectionIterator++)
            {
                <div class="initiative-section">
                    <div class="initiative-section-name">
                        <span>@Model.SectionNameWithRank.Keys.ElementAt(sectionIterator - 1)</span>
                    </div>
                    @for (sectionPracticeIterator = 1; sectionPracticeIterator <= Model.SectionNameWithQuestionCount[Model.SectionNameWithRank.Keys.ElementAt(sectionIterator - 1)]; sectionPracticeIterator++)
                    {
                        <div class="initiative-section-question initiative-questioncolumn">
                            <label>
                                @*model binding*@
                                @Html.HiddenFor(x => x.QnAs[totalPracticeIterator].QuestionId)

                                <span style="width: 20px; float:left">@Html.CheckBoxFor(x => x.QnAs[totalPracticeIterator].IsChecked)</span>
                                <span style="display: block; margin-left: 20px">@Html.Raw(Model.QnAs[totalPracticeIterator].QuestionText)</span>
                            </label><br />
                        </div>
                        <div class="initiative-section-answers initiative-answercolumn">
                            @Model.QnAs[totalPracticeIterator].AnswerText
                        </div>

                        {totalPracticeIterator += 1;}
                    }
                </div>
            }
        </div>
        <div>
            <input type="submit" class="zs-left zs-button zs-button-action zs-atp-button" name="Save" value="Save" />
        </div>
    }
</section>

Answer 1

您可能想要重命名您的 inputs 以匹配您模型的 KeyValuePair 架构，因此请替换为：

@Html.HiddenFor(x => x.QnAs[totalPracticeIterator].QuestionId)

有

@Html.Hidden(string.Format("QnAs[{0}].Key", i), /*<You Need Key's value here> Like: (_kvp.Key) */)
@Html.Hidden(string.Format("QnAs[{0}].Value.QuestionId", i), x.QnAs[/*<You Need Key's value here> Like: (_kvp.Key) */].QuestionId)

您可以试试，下面的代码获取KeyValuePair：

var _kvp = Model.QnAs.ElementAt(totalPracticeIterator)

因此，浏览器发布的数据如下所示：

QnAs[0].Key = 1
QnAs[0].Value.QuestionId = 123
QnAs[1].Key = 32
QnAs[1].Value.QuestionId = 55

Answer 2

在您的 Dictionary 对象中，将键从 int 类型更改为 string 类型，这应该有效。

控制器无法读取从 MVC 中的视图返回的模型

Controller not able to read model returned from View in MVC

c#

asp.net-mvc

model-binding

asp.net-mvc-4