EF 6 + MVC Routing

The ASP.NET Routing module is responsible for mapping incoming browser requests to particular MVC controller actions.

• Route defines the URL pattern and handler information.
• All the configured routes of an application stored in RouteTable and will be used by Routing engine to determine appropriate handler class or file for an incoming request.
• Routing is used to create user-friendly URLs.
• It can also be used to set up the startup page of the application, just like the ASP.NET Web Forms.
• The routing system enables us to create any pattern of URLs you desire and express them in a clear and concise manner.

Default Routing

When you create a new ASP.NET MVC application, the application is already configured to use ASP.NET Routing in Web.config file.

<system.webServer>
  <modules>
    <remove name="TelemetryCorrelationHttpModule" />
    <add name="TelemetryCorrelationHttpModule" 
         type="Microsoft.AspNet.TelemetryCorrelation.TelemetryCorrelationHttpModule, Microsoft.AspNet.TelemetryCorrelation" 
         preCondition="integratedMode,managedHandler" />
  </modules>
</system.webServer>

Be careful not to delete these sections because without these sections routing will no longer work.

The routes are registered in the Global.asax file by invoking a RegisterRoutes method in the Application_Start() method. A route table is created in the App_Start\RouteConfig.cs file.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;

namespace MvcWithEF6Demo
{
    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

• The MapRoute() method is an extension method and we have to define the route name which is default;
• If you want to create a new route then you can specify another name because the name can't be the same.
• In the URL there are some variables like controller, action and id.
• In the defaults it will call a Home controller, Index action and id which is optional.

Custom Routing

In many simple ASP.NET MVC applications, the default route table will work, but you can also create a custom route. You can register multiple custom routes with different names.

using System.Web.Mvc;
using System.Web.Routing;

namespace MvcWithEF6Demo
{
    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                name: "Author_Details",
                url: "authors/{id}",
                defaults: new { controller = "Author", action = "Details" }
            );

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

In the above code, the URL pattern for the Author_Details route is authors/, which specifies that any URL that starts with *domain/authors, must be handled by AuthorController.

• You will see that we haven't specified in the URL pattern because we want every URL that starts with *domain/authors should always use Details action of AuthorController.
• We have specified default controller and action to handle any URL request which starts from *domain/authors.
• MVC framework evaluates each route in sequence.
• It starts with the first configured route and if incoming URL doesn't satisfy the URL pattern of the route then it will evaluate the second route and so on.

Examples

The following table shows which Controller, Action method and Id parameter would handle different URLs considering above default route.

The controller and action values in the route are not case-sensitive and the URL route patterns are relative to the application root.