Don't fire a required validator for - asp.net-mvc

Question

I have the following model:
public class Model1
{
[Required(ErrorMessage="E1")]
public string Name { get; set; }
[Required(ErrorMessage="E2")]
[RegularExpression(".+\\#.+\\..+")]
public string Email { get; set; }
[Required(ErrorMessage="E3")]
public bool WillAttend { get; set; }
}
controller action:
public ActionResult Model1()
{
Model1 m = new Model1();
return View(m);
}
and view:
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Model1</h4>
<hr />
#Html.ValidationSummary(true, "", new { #class = "text-danger" })
<div class="form-group">
#Html.LabelFor(model => model.Name, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.Name, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.Name, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.Email, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.Email, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.Email, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
#Html.LabelFor(model => model.WillAttend, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
<div class="checkbox">
#Html.EditorFor(model => model.WillAttend)
#Html.ValidationMessageFor(model => model.WillAttend, "", new { #class = "text-danger" })
</div>
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
}
problem is required validator for WillAttend property does not work. Even in action method, ModelState.IsValid is true. Why and how to do WillAttend is required ?

Answer 1

At the moment, your required-attribute just checks whether a value was specified. Since a boolean is either true or false, the validation will never fail.
You can, mark the boolean as nullable:
public bool? WillAttend { get; set; }
or you can try to make a custom validator if you are trying to force them to check the box, such as in this link.