Route with Two optional parameters in MVC3 not working

问题

I have a following types of url used in my Application.

localhost/admin/userdetail/id

localhost/admin/userdetail/id/true

localhost/admin/userdetail/id/true/success

Here is my Admin Controller

bool inSaveAction, string status are optional

    [Authorize]
    public ActionResult UserDetail(string Id, bool inSaveAction, string status)
    {
    }

    [HttpPost, Authorize, ValidateAntiForgeryToken]
    public ActionResult SaveUserDetail(UserDetailViewModel viewModel)
    {
        User userToSave = new User();
        AdminService.UpdateUser(userToSave);
        //This is calling the above function as it sending all 3 params
        return RedirectToAction("UserDetail", new { Id = viewModel.Id, 
                           inSaveAction = true, status = "success" });
    }

Below case is not working

  @Html.ActionLink("DisplayName", "UserDetail", new { id = Model.Id })

In Global.asax

 routes.MapRoute("UserDetail",
            "UserDetail/{id}",
            new
            {
                controller = "Admin",
                action = "UserDetail",
                id = UrlParameter.Optional
            }
         );

I followed http://haacked.com/archive/2011/02/20/routing-regression-with-two-consecutive-optional-url-parameters.aspx

How can i make inSaveAction & status as optional parameter for my UserDetail action?

回答1:

You're missing the parameters in your route config. In order to make this work with different parameters optional (as in Phil Haack's post), you need to define multiple routes

routes.MapRoute("UserDetail-WithStatus", 
                "UserDetail/{id}/{inSaveAction}/{status}", 
                 new
                 {
                     controller = "Admin",
                     action = "UserDetail",
                     // nothing optional 
                 }
);

routes.MapRoute("UserDetail-WithoutStatus", 
                "UserDetail/{id}/{inSaveAction}", 
                 new
                 {
                     controller = "Admin",
                     action = "UserDetail",
                     // nothing optional 
                 }
);

routes.MapRoute("UserDetail-WithoutSaveAction", 
                "UserDetail/{id}", 
                 new
                 {
                     controller = "Admin",
                     action = "UserDetail",
                     id = UrlParameter.Optional
                 }
);

And then create links with:

@Html.ActionLink("Link", "Index", "Admin", new { id = 1, inSaveAction = true, success = "success" }, null)

You'll also need to set the optional parameters as nullable, otherwise you'll get exceptions if id or inSaveAction are missing.

public ActionResult UserDetail(int? id, bool? inSaveAction, string status)
{

}

回答2:

You can use the approach introduced here. It allows you to define one route like this

routes.MapRoute(name: "UserDetail-WithStatus", 
            url: "UserDetail/{id}/{inSaveAction}/{status}", 
             defaults: new
             {
                 controller = "Admin",
                 action = "UserDetail",
                 // nothing optional 
             }, 
             lookupParameters:new string[] { "id", "inSaveAction", "status" },
             routeValueService: new RouteValueService()

);

来源：https://stackoverflow.com/questions/14169796/route-with-two-optional-parameters-in-mvc3-not-working