How do I import a namespace in Razor View Page?

Finally found the answer.

@using MyNamespace

For VB.Net:

@Imports Mynamespace

Take a look at @ravy amiry's answer if you want to include a namespace across the app.

The first way is that use @using statement in .cshtml files, that imports a namespace to current file only, and the second:

In the "web.config" file in "Views" directory of your project (notice it is not the main web.config in project's root), find this section:

<system.web.webPages.razor>
  <pages pageBaseType="System.Web.Mvc.WebViewPage">
    <namespaces>
      <add namespace="System.Web.Mvc" />
      <add namespace="System.Web.Mvc.Ajax" />
      .
      .
      <!-- etc -->
    </namespaces>
  </pages>
</system.web.webPages.razor>

you can add your custom namespace like this:

<add namespace="My.Custom" />

that will add the namespace to all of .cshtml (and/or .vbhtml) files; also you can change views inheritance from here, like:

<pages pageBaseType="My.Custom.MyWebViewPage">

Regards.

UPDATE: Thanks to @Nick Silberstein to his reminder about areas! He said:

If you're working within an area, you must add the namespace within the Web.config under /Areas/<AreaName>/Views/ rather than /Views/

For Library

@using MyNamespace

For Model

@model MyModel

In ASP.NET MVC 3 Preview1 you can import a namespace on all your razor views with this code in Global.asax.cs

Microsoft.WebPages.Compilation.CodeGeneratorSettings.AddGlobalImport("Namespace.Namespace");

I hope in RTM this gets done through Web.config section.

I found this http://weblogs.asp.net/mikaelsoderstrom/archive/2010/07/30/add-namespaces-with-razor.aspx which explains how to add a custom namespace to all your razor pages.

Basically you can make this

using Microsoft.WebPages.Compilation;
public class PreApplicationStart
{
   public static void InitializeApplication()
   {
       CodeGeneratorSettings.AddGlobalImport("Custom.Namespace");
   }
}

and put the following code in your AssemblyInfo.cs

[assembly: PreApplicationStartMethod(typeof(PreApplicationStart), "InitializeApplication")]

the method InitializeApplication will be executed before Application_Start in global.asax

One issue that you must know is that when you import a namespace via web.config in Views folder, that namespace is imported JUST for views in that folder. Means if you want to import a namespace in an area views, you must also import that namespace, in that area's web.config file, located in area's Views folder;

For namespace and Library

@using NameSpace_Name

For Model

@model Application_Name.Models.Model_Name 

For Iterate the list on Razor Page (You Have to use foreach loop for access the list items)

@model List<Application_Name.Models.Model_Name>

@foreach (var item in Model)
   {  
          <tr>
                <td>@item.srno</td>
                <td>@item.name</td>
         </tr>  
   }

You can try this

@using MyNamespace

"using MyNamespace" works in MVC3 RTM. Hope this helps.

I think in order import namespace in razor view, you just need to add below way:

@using XX.YY.ZZ

Depending on your need you can use one of following method:

In first line/s of view add "using your.domainName;" (if it is required in specific view only)

if required in all subsequent views then add "using your.domainName;" in _ViewStart.cshtml. You can find more about this in: Where and how is the _ViewStart.cshtml layout file linked?

Or add Assembly reference in View web.config as described by others explained in: How do you implement a @using across all Views in Asp.Net MVC 3?