Question

I defined two action links in my view like below:

@Html.ActionLink("Baxter", "SearchAffaires", new { LabelName = "Baxter" })
@Html.ActionLink("Favorite", "SearchAffaires", new { OnlyFavorite = true })

I defined the two routes below:

        routes.MapRoute(
        "Search Affaire Only Label", // Route name
        "{controller}/Label/{LabelName}", // URL with parameters
        new { controller = "Affaire", action = "SearchAffaires" } // Parameter defaults
        );

        routes.MapRoute(
        "Search Affaire Only Favorite", // Route name
        "{controller}/Favorite", // URL with parameters
        new { controller = "Affaire", action = "SearchAffaires", OnlyFavorite = true } // Parameter defaults
        );

If I start my solution and point to my ‘favorite’ link, I get the following url:

http://localhost:3817/Affaire/Favorite

That’s ok for me. Now, I restart my solution (important) and I point to a ‘label’ link (for this example, my label is Baxter), I get the following url:

http://localhost:3817/Affaire/Label/Baxter

That’s ok for me. Now I didn’t restart my solution and I point to my ‘favorite’ link, I get the following url:

http://localhost:3817/Affaire/Label/Baxter?OnlyFavorite=True

As you can see, the parameter named OnlyFavorite is passed again but I didn’t expect that!

What can I do to avoid this behavour?

Thanks.

Answer 1

The problem is at the time you add the link MVC has no way of knowing which route you want to use, as it has all the parameters from the current request, LabelName is set, so it matches on the Search Affaire Only Label route.

Here’s a fix. likewise you could alternatively add a constraint that LabelName can’t be empty, so it matches on the second route:

routes.MapRoute(
    "Search Affaire Only Label",
    "{controller}/Label/{LabelName}",
    new { controller = "Affaire", action = "SearchAffaires" }
    );

routes.MapRoute(
    "Search Affaire Only Favorite",
    "{controller}/Favorite",
    new
    {
        controller = "Affaire",
        action = "SearchAffaires",
        LabelName = string.Empty,
        OnlyFavorite = true
    }
);

@Html.ActionLink("Baxter", "SearchAffaires", 
                 new { LabelName = "Baxter" })
@Html.ActionLink("Favorite", "SearchAffaires", 
                 new { LabelName = string.Empty, OnlyFavorite = true })