Default route not working in Asp.Net Core

Question

I have the following Controller & Action that I want to be the first page that is loaded when the user enters my webapp:

[Route("auth")]
public class AuthController : Controller
{
    [Route("signin")]
    public IActionResult SignIn(bool signInError)
    {
    }
}

I try to do this in my app.UseMvc options like so:

app.UseMvc(routes =>
{
    routes.MapRoute(
        name: "default",
        template: "{controller=auth}/{action=signin}/");
});

However, when I start my webapp it simply navigates to http://localhost:52608/.

If I type in http://localhost:52608/auth/signin?ReturnUrl=%2F the webpage loads correctly on the page I want to be on when the user starts the webapp.

My question is, how do I set this up so it can navigate to this page as soon as the user opens the webapp?

Answer 1

Mixed Routing It is perfectly valid to use convention-based routing for some controllers and actions and attribute routing for others. However, ASP.NET Core MVC does not allow for convention-based routes and attribute routing to exist on the same action. If an action uses attribute routing, no convention-based routes can map to that action. See the ASP.NET Core docs for more info.

More info about routing

So if you want to use attribute routing, then You can't map default path in convention based routing.

If you need to use attribute routing in this controller you can add redirect action in web.congig file. Or just remove attribute routing from that action and it will work:

public class AuthController : Controller
{
    public IActionResult SignIn(bool signInError)
    {
    }
}

Edit:

Easiest solution: Add new controller with redirect action for example:

public class HomeController : Controller
{
    public IActionResult Index()
    {
     return new RedirectToActionResult("SignIn", "Auth", new {signInError = false});
    }
}

And add default routing to this Controller

app.UseMvc(routes =>
{
    routes.MapRoute(
        name: "default",
        template: "{controller=home}/{action=index}/");
});

Answer 2

There is a separate field for defaults.

routes.MapRoute(
      name: "default",
      template: "{controller}/{action}",
      defaults: new { controller = "auth", action = "signin" }
);