How Dose MapControllerRoute() works in asp.net Core ?

mina shaker

hi
i was reading about MapControllerRoute() what i understansed that i has two main processes

defining the Route Templates and there crosponding pattern
add thos route template to the routes table (that the UseRouting() use when matching incomming request with the route template in the route table);
Run the UseEndponints() that excutes the suitable action according to the matched url

what i want to ask is the part of the defining the route template and there crospnding pattern, the app includes only one patten that are defined throught the MapControllerRoute() like below code , then i have 3 controller action in my Homecontroller class then haw many template will be added to the table

            app.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");

5 Replies

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Jignesh Kumar1y ago

Accepted answer

Hello Mina,

If you want to understand route table with debugging, you can add the below line in your code and debug,

MVC:

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    
    // Total Count the number of routes
    int routeCount = RouteTable.Routes.Count;

   // Loop through all created route

       foreach(var rout in RouteTable.Routes)
		{
			onsole.WriteLine($"route: {rout}");
		}
}

MVC Core :

app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllerRoute(
            name: "default",
            pattern: "{controller=Home}/{action=Index}/{id?}");

        // Count and log the number of endpoints (routes)
        var routeCount = endpoints.DataSources
                          .SelectMany(ds => ds.Endpoints)
                          .Count();
   

   // Loop through all created route

       foreach(var rout in endpoints.DataSources
                          .SelectMany(ds => ds.Endpoints).ToList())
		{
			onsole.WriteLine($"route: {rout}");
		}
        
        
    });

mina shaker1y ago
@Sam Hobbs then which one is correct , that why i dont like to read from the docs is all misleading and it is not for begginers
Sam Hobbs1y ago
The MapControllerRoute documentation, as in:

ControllerEndpointRouteBuilderExtensions.MapControllerRoute Method (Microsoft.AspNetCore.Builder) | Microsoft Learn

https://learn.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.builder.controllerendpointroutebuilderextensions.mapcontrollerroute?view=aspnetcore-8.0

I think is misleading. The documentation says that it Adds endpoints (plural). Yet the following:

Routing to controller actions in ASP.NET Core

https://learn.microsoft.com/en-us/aspnet/core/mvc/controllers/routing?view=aspnetcore-8.0

Says MapControllerRoute is used to create a single route.

Does (not dose) that help?
mina shaker1y ago
@Jignesh Kumar i do understand this but what i dont understand how many route will be added to the route table

Jignesh Kumar2y ago

Hello Mina,

Let's take an example for your routing,

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

Create Home controller with Index method and Details method which take id as integer parameter,

using Microsoft.AspNetCore.Mvc;

namespace YourNamespace.Controllers
{
    public class HomeController : Controller
    {
        // This method will handle requests to "/Home/Index"
        public IActionResult Index()
        {
            // Return a view or any other action result
            return View();
        }

       // This method will handle requests like "/Home/Details/5"
        public IActionResult Details(int? id)
        {
            if (id == null)
            {
                return NotFound("ID is required");
            }

           // Custom logic as per your requirement

            return View(id);
        }
    }
}