每次使用新的Guid索引时，如何获取验证消息以呈现在集合属性上？

在此示例ASP.Net MVC 4程序中，我让用户填写有关赛马的详细信息。比赛的名称以及所涉及的赛马名单。每匹马都有一个名字和年龄。

该表单使用ajax和javascript允许用户即时添加和删除马输入字段，然后在按下提交按钮时立即全部提交。

为了使此过程更容易，我使用了Matt Lunn制作的html helper。

public static MvcHtmlString EditorForMany<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, IEnumerable<TValue>>> expression, string htmlFieldName = null) where TModel : class
{
    var items = expression.Compile()(html.ViewData.Model);
    var sb = new StringBuilder();

    if (String.IsNullOrEmpty(htmlFieldName))
    {
        var prefix = html.ViewContext.ViewData.TemplateInfo.HtmlFieldPrefix;

        htmlFieldName = (prefix.Length > 0 ? (prefix + ".") : String.Empty) + ExpressionHelper.GetExpressionText(expression);
    }

    foreach (var item in items)
    {
        var dummy = new { Item = item };
        var guid = Guid.NewGuid().ToString();

        var memberExp = Expression.MakeMemberAccess(Expression.Constant(dummy), dummy.GetType().GetProperty("Item"));
        var singleItemExp = Expression.Lambda<Func<TModel, TValue>>(memberExp, expression.Parameters);

        sb.Append(String.Format(@"<input type=""hidden"" name=""{0}.Index"" value=""{1}"" />", htmlFieldName, guid));
        sb.Append(html.EditorFor(singleItemExp, null, String.Format("{0}[{1}]", htmlFieldName, guid)));
    }

    return new MvcHtmlString(sb.ToString());
}

虽然我不了解所有详细信息（请阅读博客文章），但我确实知道它将索引值更改为guid而不是顺序整数。这使我可以删除列表中间的项目，而无需重新计算索引。

这是我的MCVE代码的其余部分

HomeController.cs

public class HomeController : Controller
{
    [HttpGet]
    public ActionResult Index()
    {
        var model = new Race();

        //start with one already filled in
        model.HorsesInRace.Add(new Horse() { Name = "Scooby", Age = 10 });

        return View(model);
    }

    [HttpPost]
    public ActionResult Index(Race postedModel)
    {
        if (ModelState.IsValid)
            //model is valid, redirect to another page
            return RedirectToAction("ViewHorseListing");
        else
            //model is not valid, show the page again with validation errors
            return View(postedModel);
    }

    [HttpGet]
    public ActionResult AjaxMakeHorseEntry()
    {
        //new blank horse for ajax call
        var model = new List<Horse>() { new Horse() };
        return PartialView(model);
    }
}

模型.cs

public class Race
{
    public Race() { HorsesInRace = new List<Horse>(); }

    [Display(Name = "Race Name"), Required]
    public string RaceName { get; set; }

    [Display(Name = "Horses In Race")]
    public List<Horse> HorsesInRace { get; set; }
}

public class Horse
{
    [Display(Name = "Horse's Name"), Required]
    public string Name { get; set; }

    [Display(Name = "Horse's Age"), Required]
    public int Age { get; set; }
}

Index.cshtml

@model CollectionAjaxPosting.Models.Race
<h1>Race Details</h1>
@using (Html.BeginForm())
{
    @Html.ValidationSummary()
    <hr />
    <div>
        @Html.DisplayNameFor(x => x.RaceName)
        @Html.EditorFor(x => x.RaceName)
        @Html.ValidationMessageFor(x => x.RaceName)
    </div>
    <hr />
    <div id="horse-listing">@Html.EditorForMany(x => x.HorsesInRace)</div>
    <button id="btn-add-horse" type="button">Add New Horse</button>
    <input type="submit" value="Enter Horses" />
}

<script type="text/javascript">
    $(document).ready(function () {

        //add button logic
        $('#btn-add-horse').click(function () {
            $.ajax({
                url: '@Url.Action("AjaxMakeHorseEntry")',
                cache: false,
                method: 'GET',
                success: function (html) {
                    $('#horse-listing').append(html);
                }
            })
        });

        //delete-horse buttons
        $('#horse-listing').on('click', 'button.delete-horse', function () {
            var horseEntryToRemove = $(this).closest('div.horse');
            horseEntryToRemove.prev('input[type=hidden]').remove();
            horseEntryToRemove.remove();
        });

    });
</script>

视图/共享/EditorTemplates/Horse.cshtml

@model CollectionAjaxPosting.Models.Horse

<div class="horse">
    <div>
        @Html.DisplayNameFor(x => x.Name)
        @Html.EditorFor(x => x.Name)
        @Html.ValidationMessageFor(x => x.Name)
    </div>
    <div>
        @Html.DisplayNameFor(x => x.Age)
        @Html.EditorFor(x => x.Age)
        @Html.ValidationMessageFor(x => x.Age)
    </div>
    <button type="button" class="delete-horse">Remove Horse</button>
    <hr />
</div>

视图/主页/AjaxMakeHorseEntry.cshtml

@model IEnumerable<CollectionAjaxPosting.Models.Horse>

@Html.EditorForMany(x => x, "HorsesInRace")

数据流与此代码一起工作。一个人可以在页面上创建和删除任意数量的马条目，并且在提交表单时，所有输入的值都将提供给action方法。

但是，如果用户未输入有关Horse[Required]条目的信息，ModelState.IsValid则将再次为false，以再次显示该表单，但是不会显示Horse属性的验证消息。验证错误确实会显示在ValidationSummary列表中。

例如，如果将其Race Name与空白一起留空，Horse's Name则将显示前者的验证消息。后者将<span>使用“ field-validation-valid”类进行验证。

我非常确定，这是因为EditorForMany每次创建页面时该方法都会为每个属性创建新的Guid，因此验证消息无法与正确的字段匹配。

我该怎么做才能解决此问题？我是否需要放弃引导索引的创建，或者可以对EditorForMany方法进行更改以允许正确传递验证消息？