If you have custom types and custom ASP.NET MVC Helpers, and if you set your Visual Studio Web Project’s Build Output Path folder to something other than the default bin\ location, then you will be in for a little surprise - you will not see your custom types in the Razor Intellisense!

It appears that Razor’s Intellisense uses the assembly binding probing path of your Web Project’s root folder and the bin sub-folder.

If your Build Output Path is a sub-folder of your Web Project application base folder / root folder (although I don’t understand why you would bother) you could make a change to the web.config file and add a probing privatePath configuration such as:

1<configuration>
2    <runtime>
3        <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
4            <probing privatePath="myBin" />
5        </assemblyBinding>
6    </runtime>
7<configuration>

However, in the more likely scenario that you have a common central location for all of your assemblies that is outside of your Web Project application base folder / root folder, then unfortunately by design (for security and side-by-side execution) there is no configuration setting in .NET that is going to help. You cannot load assemblies from outside of your application base folder (via configuration in .NET) - unless they are strong named and in the GAC.

In my scenario, the Build Output Path is outside of the Web Project’s root folder, so configuration is not an option, and my assemblies are not strong named, so the GAC is not an option.

One solution is to create a Visual Studio 2010 Extension or post-build script that copies all the assemblies from my custom Build Output Path into the local bin sub-folder. That would work, although it would also slow down my build times and frankly isn’t elegant.

A better solution is to take advantage of the fact that in my scenario the bin sub-folder does not actually exist in my Web Projects. I can make it exist in Windows 7 by creating a symbolic link named bin which points to my Build Output Path - and then magically Razor Intellisense works!

Note that when you create a symbolic link you need to have Administrator privileges.

The syntax to create the symbolic link is:

1mklink /d x:\MyWebProject\bin y:\MyCommonAssembly\Bin

Recently I have been creating some custom ASP.NET MVC 3 Helpers and have been working with some customised Visual Studio 2010 Web Projects (we effectively separate our Web Areas into individual Web Projects).

When working in these customised Web Projects for Web Areas, I have faced some issues with the Razor Intellisense. As it turns out, the issues were actually due to a lack of understanding of Razor’s requirements for populating its Intellisense.

And so, here is the absolute minimal configuration needed to get Intellisense working properly in Razor for an ASP.NET MVC 3 Web Project.

(1) A Visual Studio Web Project (sorry, I have not tried Class Library Projects)

(2) A web.config file in the root of the project, with the following contents:

 1<?xml version="1.0"?>
 2<configuration>
 3  <system.web>
 4    <compilation debug="true" targetFramework="4.0">
 5      <assemblies>
 6      <add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
 7      <add assembly="System.Web.Helpers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
 8      <add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
 9      <add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
10      <add assembly="System.Web.WebPages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
11      </assemblies>
12    </compilation>
13  </system.web>
14</configuration>

This is a cut-down version of the file that is created when you create a brand new, empty MVC 3 Web Project in Visual Studio.

Razor looks to this file in order to determine which assemblies from the GAC to load into its Intellisense. The assemblies listed above are the ASP.NET MVC 3 assemblies that contain the base class for a Razor view (System.Web.Mvc.WebViewPage) and the extension methods for all the standard MVC Helpers - such as HtmlHelper which is accessed through the @Html syntax, etc.).

If you had your own MVC Helpers that were strong named and deployed to the GAC, you could add them to the assemblies element.

All assemblies that are in the Web Project’s private Bin folder are automatically loaded and made available in the Intellisense.

(3) A web.config file in the Views folder, with the following contents:

 1<?xml version="1.0"?>
 2<configuration>
 3  
 4  <configSections>
 5    <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">
 6      <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" />
 7      <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" />
 8    </sectionGroup>
 9  </configSections>
10
11  <system.web.webPages.razor>
12    <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
13    <pages pageBaseType="System.Web.Mvc.WebViewPage">
14      <namespaces>
15        <add namespace="System.Web.Mvc" />
16        <add namespace="System.Web.Mvc.Ajax" />
17        <add namespace="System.Web.Mvc.Html" />
18        <add namespace="System.Web.Routing" />
19      </namespaces>
20    </pages>
21  </system.web.webPages.razor>
22
23  <system.web>
24    <httpHandlers>
25      <add path="*" verb="*" type="System.Web.HttpNotFoundHandler"/>
26    </httpHandlers>
27
28    <!--
29        Enabling request validation in view pages would cause validation to occur
30        after the input has already been processed by the controller. By default
31        MVC performs request validation before a controller processes the input.
32        To change this behavior apply the ValidateInputAttribute to a
33        controller or action.
34    -->
35    <pages
36        validateRequest="false"
37        pageParserFilterType="System.Web.Mvc.ViewTypeParserFilter, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
38        pageBaseType="System.Web.Mvc.ViewPage, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
39        userControlBaseType="System.Web.Mvc.ViewUserControl, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
40      <controls>
41        <add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" namespace="System.Web.Mvc" tagPrefix="mvc" />
42      </controls>
43    </pages>
44  </system.web>
45
46  <system.webServer>
47    <validation validateIntegratedModeConfiguration="false" />
48
49    <handlers>
50      <remove name="BlockViewHandler"/>
51      <add name="BlockViewHandler" path="*" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" />
52    </handlers>
53  </system.webServer>
54
55</configuration>

This is exactly the same file that is created when you create a brand new, empty MVC 3 Web Project in Visual Studio.

This web.config file importantly:

(a) Declares the default class that a Razor View/page inherits from (note: System.Web.Mvc.WebViewPage contains the Html and Ajax properties that are referenced by @Html and @Ajax respectively). The class that a specific Razor View inherits from can be overridden in the Razor syntax with the keyword @inherits.

(b) Declares the namespaces that are automatically imported - instead of having to use the @using Razor syntax. This is particularly important because it is the mechanism through which the MVC Helper extension methods are made available.

And that is all you need to get Razor Intellisense working!

I recently came across the problem where the intellisense for ASP.NET markup was not appearing in Visual Studio 2008.

After doing a Google search, I had gathered and tried the following suggestions:

• In Visual Studio: Tools ➞ Options ➞ Text Editor ➞ All Languages ➞ Turn on “Auto list members”
• Reinstalling Resharper
• Deleting the HKEY\Local Machine\Software\Microsoft\VisualStudio\9.0 registry node (which then prevented Visual Studio from running!)
• Repairing Visual Studio
• Uninstalling and then reinstalling Visual Studio

And still it didn’t solve my issue - there was still no ASP.NET intellisense for me!

The solution was to right click on a .aspx page in my solution, select “Open With” and change the default setting back to “Web Form Editor”.

Somehow, someway, this had changed.

Hopefully this will save someone else a few days of hassle!