Route mapping does not work in ASP.NET Core 2.2

Question

I have always used ASP.NET MVC 4 and now I am learning ASP.NET Core in version 2.2, I am doing some tests and I noticed that the routing is not working.

I am using the standard design that is already configured.

Within Startup.cs configure the route as follows:

 public void Configure(IApplicationBuilder app, IHostingEnvironment env)
 {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseMvc(routes =>
        {
            routes.MapRoute(name: "default", template: "{controller=Home}/{action=Index}/{id?}");
        });
 }

Then insert the following on the page index.cshtml:

@Html.ActionLink("Link para a Action About no mesmo controlador", "About")

But when I see the result in View Index.cshml is returned to me:

I’m doing something wrong?

Answer 1

The project you are working on is not from the template MVC, the route you say does not work because there are no controllers or views in that structure. You started your project by choosing the Web Application option, also known as Razor Pages which has by default initial route to page index.

Taking as an example the page About, to where you wanted to create the ActionLink, note that it is composed of a Razor template (.cshmtl) with the bind to a class of PageModel (cshtml.Cs), which will control your actions in the form of events... as if they were the actions of a controller.

About.cshml

@page
@model AboutModel
@{
    ViewData["Title"] = "About";
}
<h2>@ViewData["Title"]</h2>
<h3>@Model.Message</h3>

<p>Use this area to provide additional information.</p>

About.cshtml.Cs

using Microsoft.AspNetCore.Mvc.RazorPages;

namespace WebApplication.Razor.Pages
{
    public class AboutModel : PageModel
    {
        public string Message { get; set; }

        public void OnGet()
        {
            Message = "Your application description page.";
        }
    }
}

And in this structure, for you to add a link in the Index to about, you just add in the Index.cshml the following markup:

<a asp-page="/About">About</a>

However, if you want to continue working with MVC in Asp.net core, just create your project using the templante "Web Application (Model-View-Controller)".

The structure is almost the same as the one you’re used to in MVC4, but implementation the available resources are somewhat different. And follows below recommended way of creating your ActionLink in that version.

<a asp-area="" asp-controller="Home" asp-action="About">About</a>

Answer 2

The Controller and the Views are missing, I suggest you create another project. And then you configure the controller to render the pages you want