Question

I have a model which has a boolean property and some other properties that have the DataAnnotations Required attribute.

In my view I have

@Html.CheckBoxFor(model => model.MyProduct.BloodTestEnabled, new { @class = "cb" })

However if the checkbox is not checked the value is false and this gets posted back to the controller with a instance of MyProduct.BloodTestEnabled being false but because it has an instance of MyProduct the ModelState.IsValid equals false because the Required attributes are being caught.

If the checkbox is true I only want it to post back to the controller with a new instance of MyProduct which has been created by the modelbinder.

What I have managed to do is this which fixes it but not sure if its proper:

public class MyViewModel
{
        public MyProdct MyProduct
        {
            get;
            set;
        }

        public bool BloodTestEnabled { get; set; }
}

public ActionResult Add(ProductViewModel newProducts)
        {
            if (!ModelState.IsValid)
            {
                return View("HomeIndex", newProducts);
            }

            //Some other code here
                newProducts.MyProduct.BloodTestEnabled = newProducts.BloodTestEnabled;
                _basket.AddProduct(newProducts.MyProduct);
}

Answer 1

Simply use an input tag instead. The CheckBoxFor method creates a hidden input that returns a value of True/False. It’s designed to function exactly how you are asking it not to. CheckBoxFor also does not work with lists or non Boolean values.

CheckBoxFor renders like this:

     <input checked="checked" id="BloodTestEnabled" 
    name="BloodTestEnabled" type="checkbox" value="true" />
<input name="BloodTestEnabled" 
    type="hidden" value="false" />

Your code should be something like:

<input type="checkbox" name="BloodTestEnabled" class="cb" />

You can test your input here and fine tune the HTML

http://www.w3schools.com/html/tryit.asp?filename=tryhtml_form_checkbox