ASP.NET MVC 4 Routing I just can't figure out

问题

I'm working on a project in ASP.NET MVC 4 and I'm at a bit of a loss with a particular routing. I have a lot of custom routes already in the project.

I am currently making a bunch of controllers for the frontend of the site (publicly visible part) to be able to do thing like abc.com/OurSeoFeatures that gets routed to /OurSeoFeatures/Index

Is there any way to do this so that the above would route to something like /frontend/OurSeoFeature and another page would route to /frontend/anotherpage and also still have my other routes correctly? It seems to me that the above would hit the default route and if I put something like the following it would just catch all the request and would not let me hit anything else.

        routes.MapRoute(
            name: "ImpossibleRoute",
            url: "{action}/{id}",
            defaults: new { controller = "frontend", id = UrlParameter.Optional }
        );

Am I just stuck with making a bunch of controllers? I really don't want to make one controller like page and put a bunch of actions there as I don't think its very pretty. Any Ideas?

回答1:

In order to do what you're asking, you simply need to add a route constraint:

routes.MapRoute(
    name: "Frontend",
    url: "frontend/{controller}/{action}/{id}",
    defaults: new { controller = "OurSeoFeature", action = "Index", id = UrlParameter.Optional },
    constraints: new { controller = "OurSeoFeature|Products" }
);

This constraint means the route will only match controllers with the names OurSeoFeatureController or ProductsController. Any other controller will trigger the default route. However, this wouldn't handle redirecting those controllers to /frontend/..., if that's what you're after. Instead, that gets a little more involved.

Firstly, you'll need to create a class that implements IRouteConstraint, in order to supply the controller names you want to redirect to /frontend/.... The reason we need this now, is because we'll need to access those names in an ActionFilter, and we can't do that if we supply a regex constraint like constraints: new { controller = "OurSeoFeature|Products" above. So, the constraint could look something like this:

public class FrontendControllerConstraint : IRouteConstraint
{
    public FrontendControllerConstraint()
    {
        this.ControllerNames = new List<string> { "OurSeoFeature", "Products" }; 
    }

    public bool Match(HttpContextBase httpContext, Route route,
        string parameterName, RouteValueDictionary values,
        RouteDirection routeDirection)
    {
        string value = values[parameterName].ToString();

        return ControllerNames.Contains(value, StringComparer.OrdinalIgnoreCase);
    }

    public List<string> ControllerNames { get; private set; }
}

Next up, the action filter could look like this:

public class RedirectToFrontendActionFilter : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        var controller = filterContext.RouteData.Values["controller"].ToString();
        var path = filterContext.HttpContext.Request.Url.AbsolutePath;
        var controllersToMatch = new FrontendControllerConstraint().ControllerNames;

        if (controllersToMatch.Contains(controller, StringComparer.OrdinalIgnoreCase)
            && path.IndexOf(pathPrefix, StringComparison.OrdinalIgnoreCase) == -1)
        {
            filterContext.Result =
                new RedirectToRouteResult(routeName, filterContext.RouteData.Values);
        }

        base.OnActionExecuting(filterContext);
    }

    private string routeName = "Frontend";
    private string pathPrefix = "Frontend";
}

Now that we have those in place, all that's left is to wire it all up. Firstly, the constraint is applied in a slightly different way:

routes.MapRoute(
    name: "Frontend",
    url: "frontend/{controller}/{action}/{id}",
    defaults: new { controller = "OurSeoFeature", action = "Index", id = UrlParameter.Optional },
    constraints: new { controller = new FrontendControllerConstraint() }
);

Finally, you need to add the filter to FilterConfig.cs:

public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
    filters.Add(new HandleErrorAttribute());
    filters.Add(new RedirectToFrontendActionFilter());
}

One warning here is that because I'm checking against Request.Url.AbsolutePath, you cannot pass anything in the path that contains the word frontend. So make sure all controllers, actions and route values added to the path, do not contain that. The reason is that I'm checking for the existence of /frontend/ in the path, to ensure that the matched controllers will only redirect to that route if they they're not already using it.

There are a lot of added things you could do with that setup, but I don't know your requirements. As such, you should treat this code simply as a skeleton to get started, making sure to test that it does what you want it to do.

Updated per comments

I'll leave everything above there, just in case someone finds that useful. To address what you'd like to do, however, we need a different approach. Again, we need some route constraints, but the way I see this working is to flip your idea on its head and make the frontend the default route. Like so:

routes.MapRoute(
    name: "Backend",
    url: "{controller}/{action}/{id}",
    defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional },
    constraints: new { controller = "Home|Backend" }
);

routes.MapRoute(
    name: "Default",
    url: "{action}/{id}",
    defaults: new { controller = "Frontend", action = "Index", id = UrlParameter.Optional },
    constraints: new { action = "Index|OurSeoFeature" }
);

Just as before, I've applied some constraints to get the correct behaviour. In particular, for this constraint:

constraints: new { controller = "Home|Backend" }

if you have a lot of controllers that aren't part of the frontend, it might be an idea to implement IRouteConstraint to keep a list of the controller names there. You could even go as far as deriving all of your backend controllers from a base controller, so you can grab all of them with reflection in the IRouteConstraint implementation. Something like this:

public BackendController : Controller
{
    // 
}

Then:

public AdminController : BackendController
{
    //
}

Constraint:

public class BackendConstraint : IRouteConstraint
{
    // Get controller names based on types that
    // BackendController
}

This same idea also applies to getting the action names of FrontendController for the second constraint. The only thing you need to be careful of here is that you don't have any backend controllers which have the same name as an action on your FrontendController, because it will match the wrong route.

回答2:

I appreciate the question is over a year old with an accepted answer but the accepted answer involves route constraints when none are necessary. It's really just as simple as:

routes.MapRoute("SEO", "OurSeoFeatures",
               new { controller = "frontEnd", action = "OurSeoFeatures"});

回答3:

The basic idea of the route is controller/action.

So if you want to hit the OurSeoFeatures controller's index action then you have to give your route like

routes.MapRoute(
            name: "BasicController",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "OurSeoFeatures",action="Index", id = UrlParameter.Optional }
        );

In your case you have left out the controller from your route url. Please specifiy the controller also as part of URL and have a default controller.

来源：https://stackoverflow.com/questions/20866860/asp-net-mvc-4-routing-i-just-cant-figure-out