I have the following route defined
routes.MapRoute(
\"ItemName\",
\"{controller}/{action}/{projectName}/{name}\",
When constructing and matching routes in ASP.NET routing (which is what ASP.NET MVC uses), the first appropriate match is used, not the greediest, and order is important.
So if you have two routes:
"{controller}/{action}/{id}"
"{controller}/{action}/{projectName}/{name}"
in that given order, then the first one will be used. The extra values, in this case projectName and name, become query parameters.
In fact, since you've provided default values for {projectName} and {name}, it's fully in conflict with the default route. Here are your choices:
Remove the default route. Do this if you don't need the default route any more.
Move the longer route first, and make it more explicit so that it doesn't match the default route, such as:
routes.MapRoute(
"ItemName",
"Home/{action}/{projectName}/{name}",
new { controller = "Home", action = "Index", name = "", projectName = "" }
);
This way, any routes with controller == Home will match the first route, and any routes with controller != Home will match the second route.
Use RouteLinks instead of ActionLinks, specifically naming which route you want so that it makes the correct link without ambiguity.
You can try
Html.RouteLink("Edit","ItemName", new {name=m.name, projectName=m.Project.title});
Just to clear up, here is what I finally did to solve it, thanks to the answer from @Brad
<%=Html.RouteLink("Edit", "ItemName", new { projectName=m.Project.title, name=m.name, controller="Milestone", action="Edit"})%>