KeyNotFound Exception when calling Html.ValidationSummary() dynamically through helper method

Question

Hi,

I have a Helper Method in my View which renders the whole form dynamically. Now i want to add a support for Client Validation as available in Asp.Net MVC RC 2.

Following is the code i use to render Validation Summary field onto the Form.

_viewPage.Html.EnableClientValidation();
        MvcHtmlString validationSummary = _viewPage.Html.ValidationSummary("There are errors on this form. Please contact your administrator.");
        if (validationSummary != null && validationSummary.ToString() != "")
            Response.Write(validationSummary.ToString());

When code reaches this point i get following error.

System.Collections.Generic.KeyNotFoundException was unhandled by user code

Message="The given key was not present in the dictionary." Source="System" StackTrace: at System.ThrowHelper.ThrowKeyNotFoundException() at System.Collections.Generic.SortedDictionary2.get_Item(TKey key) at System.Web.Mvc.Html.ValidationExtensions.ValidationSummary(HtmlHelper htmlHelper, Boolean excludePropertyErrors, String message, IDictionary2 htmlAttributes) at System.Web.Mvc.Html.ValidationExtensions.ValidationSummary(HtmlHelper htmlHelper, String message, IDictionary`2 htmlAttributes) at Fusion.UI.MvcWebUX.Helper.FormGenerator.GenerateFormValidation() in D:\EBS\Project.Fusion\Fusion.UI.MvcWebUX\Helper\FormGenerator.cs:line 88 at Fusion.UI.MvcWebUX.Helper.FormGenerator.GenerateForm() in D:\EBS\Project.Fusion\Fusion.UI.MvcWebUX\Helper\FormGenerator.cs:line 70 at Fusion.UI.MvcWebUX.Helper.FormGenerator.RenderForm(ViewPage viewPage) in D:\EBS\Project.Fusion\Fusion.UI.MvcWebUX\Helper\FormGenerator.cs:line 60 at ASP.views_shared_autoview_aspx.__RenderContent2(HtmlTextWriter __w, Control parameterContainer) in d:\EBS\Project.Fusion\Fusion.UI.MvcWebUX\Views\Shared\AutoView.aspx:line 7 at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) at System.Web.UI.Control.Render(HtmlTextWriter writer) at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer) at ASP.views_shared_fusion_master._Render_control1(HtmlTextWriter __w, Control parameterContainer) in d:\EBS\Project.Fusion\Fusion.UI.MvcWebUX\Views\Shared\Fusion.Master:line 74 at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) at System.Web.UI.Control.Render(HtmlTextWriter writer) at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer) at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) at System.Web.UI.Page.Render(HtmlTextWriter writer) at System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer) at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) at System.Web.UI.Control.RenderControl(HtmlTextWriter writer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) InnerException:

I have struggling with this for few hours. Can anyone help me to solve it and tell me why would this be happening.

Answer 1

I have found the problem to it. I had been setting EnableClientValidation after writing BeginForm. Just write _viewPage.Html.EnableClientValidation(); before anything on the Form and the error was solved. Thanks,

Answer 2

I've come here twice for the solution, so I'll also answer with another thing that can cause this.

In MVC2 RC (I believe; the version delivered with 2010 RC), you can cause this exception when calling EnableClientValidation:

<%-- This is the proper way to call these two methods --%>
<% Html.ValidationSummary(); %>
<% Html.EnableClientValidation(); %>

This way will cause the exception:

<%-- Side effects of calling ECV first will result in the exception --%>
<% Html.EnableClientValidation(); %>
<% Html.ValidationSummary(); %>

Pretty crappy to have side effects crop up from a couple disconnected method calls like this. Kinda reminds me of global variables.