asp.net mvc: why is Html.CheckBox generating an additional hidden input

Question

I just noticed that Html.CheckBox(\"foo\") generates 2 inputs instead of one, anybody knows why is this so ?

Answer 1

This is the strongly typed version of Alexander Trofimov's solution:

using System.Web.Mvc;
using System.Web.Mvc.Html;

public static class HelperUI
{
    public static MvcHtmlString CheckBoxSimpleFor(this HtmlHelper htmlHelper, Expression> expression, object htmlAttributes)
    {
        string checkBoxWithHidden = htmlHelper.CheckBoxFor(expression, htmlAttributes).ToHtmlString().Trim();
        string pureCheckBox = checkBoxWithHidden.Substring(0, checkBoxWithHidden.IndexOf("