Routing in Asp.NET MVC is how ASP.NET MVC matches a URI to an action. ASP.NET routing enables you to use URLs that do not have to map to specific files in a Web site. Because the URL does not have to map to a file, you can use URLs that are descriptive of the user's action and therefore are more easily understood by users. It is a part of all the MVC versions but MVC 5 supports a new type of routing, called attribute routing. As the name implies, attribute routing uses attributes to define routes. Attribute routing gives you more control over the URIs in your web application. There is a separate article to understand Attributes in Routing in ASP.NET MVC.

1. 7/16/2014 Understanding Routing in ASP.NET MVC with example
http://www.dotnet-stuff.com/tutorials/aspnet-mvc/understanding-routing-in-asp-net-mvc-with-example 1/5
R
Understanding Routing in ASP.NET MVC with example
Posted Date: 26. May 2014 Posted By: Anil Sharma
Categories: ASP.NET MVC, ASP.NET
Keywords: Routing in ASP.NET MVC, MVC Routing Example, Routing in MVC, Define Routing
outing in Asp.NET MVC is how ASP.NET MVC matches a URI to an action. ASP.NET routing enables you to
use URLs that do not have to map to specific files in a Web site. Because the URL does not have to map to a
file, you can use URLs that are descriptive of the user's action and therefore are more easily understood by users. It
is a part of all the MVC versions but MVC 5 supports a new type of routing, called attribute routing. As the name
implies, attribute routing uses attributes to define routes. Attribute routing gives you more control over the URIs in
your web application. There is a separate article to understand Attributes in Routing in ASP.NET MVC.
How to define Routing in MVC?
If you adopt the MVC convention of implementing controllers by creating classes that derive from the ControllerBase
class and giving them names that end with "Controller", you do not need to manually add routes in an MVC
application. The preconfigured routes will invoke the action methods that you implement in the controller classes.
You may also want to add custom routes in an MVC application, than you need to use the
MapRoute(RouteCollection, String, String) method instead of the MapPageRoute(String, String, String) method.
Once you have decide the Routing for your application, you need to register it and make sure that you are calling
this register method at Application_Start() event of your application. The following example shows the code that
creates default MVC routes in the Global.asax file, as defined in the Visual Studio project template for MVC
applications.
 


1
2
3
4
5
6
7
8
9
10
publicclassMvcApplication:System.Web.HttpApplication
{
publicstaticvoidRegisterRoutes(RouteCollectionroutes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapRoute(
"Default", //Routename
"{controller}/{action}/{id}", //URLwithparameters
new{controller="Home",action="Index",id=""} //Parameterdefaultsvaluefor

2. 7/16/2014 Understanding Routing in ASP.NET MVC with example
http://www.dotnet-stuff.com/tutorials/aspnet-mvc/understanding-routing-in-asp-net-mvc-with-example 2/5
Always remember route name should be unique across the entire application. Route name can’t be duplicate.
How to set Default Value for Routing in ASP.NET MVC?
Now you are able to define the routing in MVC. When you define a route, than you can still assign a default value for
a parameter. This default value is used if a value for that parameter is not included in the URL. You can set default
values for a route by assigning a dictionary object to the Defaults property of the Route class. The following example
shows how to add a route that has default values, by using the MapPageRoute(String, String, String, Boolean,
RouteValueDictionary) method.
As you can see in above code, ASP.NET routing handles a URL request, the route definition shown in the example
(with default values of MVC for categoryName and show for action) produces the results that are listed in the
following table.
URL Parameter values
11
12
13
14
15
16
17
18
19
);
}
protectedvoidApplication_Start()
{
RegisterRoutes(RouteTable.Routes);
}
}
1
2
3
4
5
6
7
8
9
10
11
12
13
publicstaticvoidRegisterRoutes(RouteCollectionroutes)
{
routes.MapPageRoute("",
"Category/{action}/{categoryName}",
"~/categories.aspx",
true,
newRouteValueDictionary
{{"categoryName","MVC"},{"action","show"}});
}
voidApplication_Start(objectsender,EventArgse)
{
RegisterRoutes(RouteTable.Routes);
}

3. 7/16/2014 Understanding Routing in ASP.NET MVC with example
http://www.dotnet-stuff.com/tutorials/aspnet-mvc/understanding-routing-in-asp-net-mvc-with-example 3/5
/Category
action = "show" (default value)
categoryName = "MVC" (default value)
/Category/add
action = "add"
categoryName = "MVC" (default value)
/Category/add/routingexample action = "add" categoryName= "routingexample"
How Routing is work in ASP.NET MVC?
To make better understanding of work flow of MVC Routing consider a diagram given below.
In above diagram, you can see that when any user make request for any URL, the system check in
RouteTable.Routes (Collection of all the Routes). It parses the route and match with current URL. If there are any
constraints or attributes are found than it process the constraints and check whether it satisfy than it will Build and

4. 7/16/2014 Understanding Routing in ASP.NET MVC with example
http://www.dotnet-stuff.com/tutorials/aspnet-mvc/understanding-routing-in-asp-net-mvc-with-example 4/5
returns RouteData and page will be served , otherwise it will returns null and Page Not Found with Status code 404
can be returned.
To understand how Routing is works in MVC at macro level, we have following diagram shows how it is done.
The main function of the UrlRoutingModule is to tell the IIS to use IHttpHandler which I got from the matched route.
And IIS do the same and returns the result to the browser.
Summary: I Hope you have enjoyed this article and now you are able to define routing in ASP.NET MVC application.
Although, you need to know something more about attributes in Routing. Thus I have written this in a separate
article to understand attributes in Routing in ASP.NET MVC.
Keen to here from you...!
If you have any questions related to what's mentioned in the article or need help with any issue, ask it, I would love to
here from you. Please MakeUseOf Contact and i will be more than happy to help.
About the author
Anil Sharma is Chief Editor of dotnet-stuff.com. He's a software professional
and loves to work with Microsoft .Net. He's usually writes articles about .Net
related technologies and here to shares his experiences, personal notes,

5. 7/16/2014 Understanding Routing in ASP.NET MVC with example
http://www.dotnet-stuff.com/tutorials/aspnet-mvc/understanding-routing-in-asp-net-mvc-with-example 5/5
Tutorials, Examples, Problems & Solutions, Code Snippets, Reference
Manual and Resources with C#, Asp.Net, Linq , Ajax, MVC, Entity
Framework, WCF, SQL Server, jQuery, Visual Studio and much more...!!!
Connect with the author: • Google + • Linkedin