Recently I faced a challenge while trying to programatically register routes on a .net core MVC application. The following was my code.

app.UseMvc(routeBuilder =>
                 {
                     routeBuilder.MapRoute(
                         name: "example-route",
                         template: "example",
                         defaults: new { controller = "ExampleController", action = "ExampleAction" }
                     );
});

Once the route was registered, I tried navigating to it and I kept getting a 404. Was breaking my head as to why this was happening. Finally found the issue.

The controller name cannot have the post-fix Controller, the following change made the trick.

app.UseMvc(routeBuilder =>
                 {
                     routeBuilder.MapRoute(
                         name: "example-route",
                         template: "example",
                         defaults: new { controller = "ExampleController", action = "ExampleAction" }
                     );
});

Hope this helps someone, break their head over this trivial thing.

Cheers!