Cannot get my html input array to serialize into a List<string> in Asp.Net mvc

I am attempting to implement a tagging system into my asp.net MVC project. When a user edits or adds a task, they can add any amount of tags they want before submitting. I am using the Jquery Tagit plugin, so when a user adds a new tag an input field is created that looks like:

<input type="hidden" style="display:none;" value="tag1" name="Tags[]">

When the user presses the submit button after adding a few tags, the browser sends the following querystring to the server (retrieved via fiddler):

IsNew=True&Id=2222&Title=Test+Title&Description=Test+Description&Tags%5B%5D=Tag1&Tags%5B%5D=blah&Tags%5B%5D=another-tag

Now my viewmodel that I am serializing this data into 开发者_如何转开发has the following structure:

public class KnowledgeBaseTaskViewModel
{
    public int Id { get; set; }

    [Required(AllowEmptyStrings=false, ErrorMessage="Task title is required")]
    [StringLength(500)]
    public string Title { get; set; }

    [Required(AllowEmptyStrings=false, ErrorMessage="Task description is required")]
    [StringLength(500)]
    public string Description { get; set; }

    public List<string> Tags { get; set; }
    public bool IsNew { get; set; } // Needed to determine if we are inserting or not
}

Finally my receiving action has the following signature:

    [HttpPost]
    public ActionResult EditTask(KnowledgeBaseTaskViewModel task)

The issue is that my tag list is not serializing correctly, and my List Tags is null. I have looked at various questions on this site on how to serialize arrays but I still cannot see what I am doing wrong. Any help is greatly appreciated.

It sounds like what you've got should work, but try changing the type of Tags property from List to IList. the model binder might not be using the concrete List<> type.

also, check out this article by Phil Haack: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx