Question

I have an action method that looks like this:

public ActionResult DoSomething(string par, IEnumerable<string> mystrings)

I wanted to map this to a URL using Url.Action, passing mystrings in the RouteValueDictionary. However, this only yields a query string that only corresponds to mystrings.ToString().

How could I pass a list in the query string? Is there some functionality in MVC 2 that supports this?

CLARIFICATION: The action method is called using GET, not POST.

There is no problem for my action method to parse the query string DoSomething?mystrings=aaa&mystrings=bbb

However, I cannot generate this using Url.Action. Passing a list generates the following query string: mystrings=system.collections.generic.list%601%5bsystem.string%5d

Is there some way I could accomplish this easily?

Answer 1

Yes. Model Binding To A List

EDIT: Ok, now I see where you’re going with this. I don’t think ASP.NET MVC has that built-in since it’s designed to generate query strings from route values that have unique names. You may have to roll your own. I would create an extension method on IEnumerable<String> like this:

public static class Extensions
{
    public static string ToQueryString(this IEnumerable<string> items)
    {
        return items.Aggregate("", (curr, next) => curr + "mystring=" + next + "&");
    }
}

Then you could generate your own query string like this:

<%= Url.Action("DoSomething?" + Model.Data.ToQueryString()) %>

This needs some polish as you should UrlEncode your strings and it creates a trailing “&”, but this should give you the basic idea.