从MVC2.0Beta升级的ASP.Net MVC RCA2.0验证问题

Question

我们最近刚刚升级了我们的应用程序，并注意到我们在所有的Html.ValidationMessages和Html.ValidationMessageFor上都有运行时错误。错误是：给定的键在字典中不存在。我们一直在传递模型名/表达式，在升级之前它运行良好。我还检查了自述的突破性更改，但没有注意到与其相关的任何内容。

Answer 1

在调试了ASP.NET MVC源代码之后，我发现了这个问题的原因。

您必须在<% <%= %>之前使用Html.EnableClientSideValidation %>，原因是当启用客户端验证时，helper将生成在验证助手中使用的Id (formContext.FormId)。这意味着，如果要使用验证助手，就必须使用内置的表单帮助程序。

因此，要解决这个问题，只需将<%= Html.EnableClientSideValidation %>移到第一个表单的上方，并确保使用Html.BeginForm助手方法。

Answer 2

莱维，我知道你是asp.net mvc团队的一员，你能提供一些指导吗？

这是错误。

Line 185:                // rules will already have been written to the metadata object
Line 186:                fieldMetadata.ReplaceValidationMessageContents = (String.IsNullOrEmpty(validationMessage)); // only replace contents if no explicit message was specified
Line 187:                fieldMetadata.ValidationMessageId = builder.Attributes["id"];
Line 188:            }
Line 189:

这是痕迹。

[KeyNotFoundException: The given key was not present in the dictionary.]
   System.ThrowHelper.ThrowKeyNotFoundException() +29
   System.Collections.Generic.SortedDictionary`2.get_Item(TKey key) +5167507
   System.Web.Mvc.Html.ValidationExtensions.ValidationMessageHelper(HtmlHelper htmlHelper, ModelMetadata modelMetadata, String expression, String validationMessage, IDictionary`2 htmlAttributes) in D:\Projects\Practice\Mercurial\onlinerestaurant\trunk\ReferenceProjects\aspnetmvc2-rc-sources\src\SystemWebMvc\Mvc\Html\ValidationExtensions.cs:187
   System.Web.Mvc.Html.ValidationExtensions.ValidationMessageFor(HtmlHelper`1 htmlHelper, Expression`1 expression, String validationMessage, IDictionary`2 htmlAttributes) in D:\Projects\Practice\Mercurial\onlinerestaurant\trunk\ReferenceProjects\aspnetmvc2-rc-sources\src\SystemWebMvc\Mvc\Html\ValidationExtensions.cs:146
   System.Web.Mvc.Html.ValidationExtensions.ValidationMessageFor(HtmlHelper`1 htmlHelper, Expression`1 expression) in D:\Projects\Practice\Mercurial\onlinerestaurant\trunk\ReferenceProjects\aspnetmvc2-rc-sources\src\SystemWebMvc\Mvc\Html\ValidationExtensions.cs:131
   ASP.views_admin_createmenucategory_ascx.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in d:\Projects\Practice\Mercurial\onlinerestaurant\trunk\OnlineRestaurant\Views\Admin\CreateMenuCategory.ascx:26
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +256
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
   System.Web.UI.Control.Render(HtmlTextWriter writer) +10
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
   System.Web.UI.Page.Render(HtmlTextWriter writer) +29
   System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer) in D:\Projects\Practice\Mercurial\onlinerestaurant\trunk\ReferenceProjects\aspnetmvc2-rc-sources\src\SystemWebMvc\Mvc\ViewPage.cs:107
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266