"ASP.global_asax does not exist in the namespace ASP"

Question

I created a RazorFunctions.cshtml file on App_Code

@functions {     public static string GetActiveClassIf(string controllerName, string actionName = null)     {         var routeData = @HttpContext.Current.Request.RequestContext.RouteData;         string currentController = routeData.Values["controller"].ToString();         string currentAction = routeData.Values["action"].ToString();         return controllerName == currentController &&             (String.IsNullOrEmpty(actionName) || currentAction == actionName) ? "active" : "";     } } 

and when I compile, it give me 2 errors (compilation get success and site work without problem) but the errors are annoying.

The RazorFunctions.cshtml are as Content (tried compile but doesn't work with cshtml files of course)

Global.asax.cs is :

public class MvcApplication : System.Web.HttpApplication {     protected void Application_Start()     {         AreaRegistration.RegisterAllAreas();         ModelMetadataConfig.RegisterModelMetadata();         FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);         RouteConfig.RegisterRoutes(RouteTable.Routes);         BundleConfig.RegisterBundles(BundleTable.Bundles);         Database.SetInitializer(new MigrateDatabaseToLatestVersion<ApplicationDbContext, Configuration>());         //Database.SetInitializer(new DropCreateDatabaseAlways<ApplicationDbContext>());     } } 

and

<%@ Application Codebehind="Global.asax.cs" Inherits="Bouron.Web.MvcApplication" Language="C#" %> 

This is the first time I use the App_Code so I don't know what else to do, all search returns ASP.NET 1-2 results, are out of date where razor doesn't even exist so I'm not sure how can I solve this.

I'm using Visual Studio 2015 (just in case it matters)

Answer 1

After further investigation I found that this is a known issue.

source: https://support.microsoft.com/en-us/kb/3025133

ASP.NET and Web Development

• When you create a Web Forms 4.5 WAP and open a Web Form page, you receive the following errors in the Errors List window:

• The project will run without any issues. Error CS0234 The type or namespace name 'global_asax' does not exist in the namespace 'ASP' (are you missing an assembly reference?) Error CS0234 The type or namespace name 'Linq' does not exist in the namespace 'System' (are you missing an assembly reference?) Assume that you use new language features for C# and VB in Visual Studio 2015 RC. You receive a runtime error when you use C# or VB in a Web Form page or in Razor Views.

To work around this issue, install Microsoft.CodeDom.Providers.DotNetCompilerPlatform NuGet package. This package will substitute the Roslyn-based provider for the in-box CodeDom providers for ASP.NET.