asp.net-mvc - ModelState 中需要 DateTime，但从未设置为

Question

我的表单中有一个 DateTime 字段。无论出于何种原因，每次我提交表单时，ModelState 都会返回无效，并且会提示我的日期时间字段(称为 PostDate)是必需的，即使在 View 模型中我没有设置所需的属性。

有谁知道为什么会发生这种情况，因为我绕着圈子试图弄清楚。

这是 View 模型

public class BlogViewModel
        {
            [Required]
            public string Title { get; set; }
            [Required]
            public string Content { get; set; }
            public bool Published { get; set; }
            public DateTime PostDate { get; set; }
        }

这里是 Controller Action

            public ActionResult Create()
            {
                return View();
            } 

            //
            // POST: /Admin/Blog/Create

            [HttpPost]
            [ValidateInput(false)]
            public ActionResult Create(BlogViewModel model)
            {
                if(ModelState.IsValid)
                {
                    model.Content = HtmlSanitizer.SanitizeHtml(model.Content);
                    Services.BlogService.CreateBlogPost(model.Title, model.Content, User.Identity.Name);
                    return RedirectToAction("Index");
                }
                return View(model);
            }

这里是 View

    @using Payntbrush.Infrastructure.Mvc.Extensions
    @model Payntbrush.Presentation.Demo.MVC3.Areas.Admin.Models.BlogViewModel

    @Html.Resource(Html.ScriptTag("Areas/Admin/js/plugins/wysiwyg/jquery.wysiwyg.js"), ResourceType.Js)


    <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>

    @using (Html.BeginForm((string)ViewBag.Action, "Blog", FormMethod.Post, new { Id = "BlogEditor" }))
    {
        @Html.ValidationSummary(true)

            <div class="editor-label">
                @Html.LabelFor(model => model.Title)
            </div>
            <div class="editor-field">
                @Html.EditorFor(model => model.Title)
                @Html.ValidationMessageFor(model => model.Title)
            </div>

            <div class="editor-label">
                @Html.LabelFor(model => model.Content)
            </div>
            <div class="editor-field">
                @Html.TextAreaFor(model => model.Content, new { @class = "wysiwyg blog-editor" })
                @Html.ValidationMessageFor(model => model.Content)
            </div>

            <div class="editor-label">
                Time of post (Only set this if you want to make a post appear to have been published at a different date.)
            </div>
            <div class="editor-field">
                @Html.TextBoxFor(model => model.PostDate, new{@class="datetimepicker"})
                @Html.ValidationMessageFor(model => model.PostDate)
            </div>

            <div class="editor-label">
                Published (Check to make this post live on the site)
            </div>
            <div class="editor-field">
                @Html.CheckBoxFor(model => model.Published)
                @Html.ValidationMessageFor(model => model.Published)
            </div>

            <p>
                <input class="large awesome" type="submit" value="Create" />
                @Html.ActionLink("Cancel", "Index", "Blog", null, new { @class = "large awesome cancel-button" })
            </p>
    }

    <div>

    </div>

Answer 1

如果您将相应字段留空，您的模型将无效，因为 DateTime 是一种值类型。如果要允许空值，则应使用可为空的 DateTime:

public DateTime? PostDate { get; set; }