问绑定不起作用

EN

@using PerpetuumSoft.Knockout

helloworld thing
@model koHelloworld.Models.HelloWorldModel
@{
    var ko = Html.CreateKnockoutContext();
}
<p>First name: @ko.Html.TextBox(m => m.FirstName)</p>
<p>Last name: @ko.Html.TextBox(m => m.LastName)</p>
<h2>Hello, @ko.Html.Span(m => m.FullName)!</h2>

@ko.Apply(Model)

namespace koHelloworld.Models
{
    public class HelloWorldModel
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }

        [Computed]
        public string FullName
        {
            get { return FirstName + " " + LastName; }
        }
    }
}

public class HelloWorldController : BaseController
{
    public ActionResult Index()
    {
        InitializeViewBag("Hello world");
        return View(new HelloWorldModel
        {
            FirstName = "Steve",
            LastName = "Sanderson"
        });
    }
}