Html.Hidden field not getting set

Question

I have a hidden field in my view like this:

using (Html.BeginForm(\"Action\", \"Schedule\"))
{
    @Html.Hidden(\"Id\", Model.Schedule.Id)
    ...
}
<         


        

Answer 1

Figured this out with the help of this question: MVC3 Model Binding - List to Hidden fields

Apparently HTML helpers check ModelState for a value before they check Model. The reason why I only saw this behavior when I added the Id as a parameter to the action method was that this invoked the model binder to populate ModelState with the Id. And the reason why the Id was always an empty Guid was because that's the value the first time the action method is called.

I added this line to my action method and everything works fine now:

ModelState.Remove("Id")