Razor Views Not Seeing System.Web.Mvc.Htmlhelper

Razor can not find my HTML helper

It needs to be added to the config file in the Views folder, not the main config.

See this answer:

How do I import a namespace in Razor View Page?

Razor HtmlHelper Extensions (or other namespaces for views) Not Found

Since the Beta, Razor uses a different config section for globally defining namespace imports. In your Views\Web.config file you should add the following:

<configSections>
  <sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
    <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
    <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
  </sectionGroup>
</configSections>

<system.web.webPages.razor>
  <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
  <pages pageBaseType="System.Web.Mvc.WebViewPage">
    <namespaces>
      <add namespace="System.Web.Mvc" />
      <add namespace="System.Web.Mvc.Ajax" />
      <add namespace="System.Web.Mvc.Html" />
      <add namespace="System.Web.Routing" />
      <!-- Your namespace here -->
    </namespaces>
  </pages>
</system.web.webPages.razor>

Use the MVC 3 upgrade tool to automatically ensure you have the right config values.

Note that you might need to close and reopen the file for the changes to be picked up by the editor.

Why can't Razor find my HTML Helper?

Have you added the helper's namespace to your Views/web.config?

  <system.web.webPages.razor>
    <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
    <pages pageBaseType="System.Web.Mvc.WebViewPage">
      <namespaces>
        <add namespace="System.Web.Mvc" />
        <add namespace="System.Web.Mvc.Ajax" />
        <add namespace="System.Web.Mvc.Html" />
        <add namespace="System.Web.Routing" />
        <add namespace="CUSTOM_NAMESPACE" />
      </namespaces>
    </pages>
  </system.web.webPages.razor>

The above will only work if you're using an RC, if you're on an early Beta, you'll need to add the namespace in the page or Global.asax.

Also, I'd suggest changing the return type to HtmlString.

return new HtmlString(STRING_VALUE);

System.Web.Webpages.Html.Htmlhelper' does not contain a definition for 'Sitecore'

I have now resolved this issue. I simply had to install Update 2 of Visual Studio 2013. How frustrating.

Thanks to StriplingWarrior and Ahmed Okour for your useful advice.

---

Related Topics