Passing IEnumerable property in RouteValues of ActionLink

Question

Imagine an object defined like :

public class MyViewModel{
    public List<string> MyList { get; set; }
}

In my view, i have this Action link :

@Ajax.ActionLink("<", "Index", new MyViewModel() { MyList = new List<string>() {"foo", "bar"}}, new AjaxOptions())

The html result of the ActionLink will be :

<a class="btn btn-default" data-ajax="true" href="/Index?MyList=System.Collections.Generic.List%601%5BSystem.String%5D">&lt;</a>

My question is, how get this result rather :

<a class="btn btn-default" data-ajax="true" href="/Index?MyList=foo&MyList=bar">&lt;</a>

Answer 1

With Stephen's anwser, i have develop a helper extension method to do this.

Be careful of the URL query string limit : if the collection has too many values, the URL can be greater than 255 characters and throw an exception.

public static class AjaxHelperExtensions
{
    public static MvcHtmlString ActionLinkUsingCollection(this AjaxHelper ajaxHelper, string linkText, string actionName, object model, AjaxOptions ajaxOptions, IDictionary<string, object> htmlAttributes)
    {
        var rv = new RouteValueDictionary();
        foreach (var property in model.GetType().GetProperties())
        {
            if (typeof(ICollection).IsAssignableFrom(property.PropertyType))
            {
                var s = ((IEnumerable<object>)property.GetValue(model));
                if (s != null && s.Any())
                {
                    var values = s.Select(p => p.ToString()).Where(p => !string.IsNullOrEmpty(p)).ToList();
                    for (var i = 0; i < values.Count(); i++)
                        rv.Add(string.Concat(property.Name, "[", i, "]"), values[i]);
                }
            }
            else
            {
                var value = property.GetGetMethod().Invoke(model, null) == null ? "" : property.GetGetMethod().Invoke(model, null).ToString();
                if (!string.IsNullOrEmpty(value))
                    rv.Add(property.Name, value);
            }
        }
        return AjaxExtensions.ActionLink(ajaxHelper, linkText, actionName, rv, ajaxOptions, htmlAttributes);
    }
}