@Html.EditorFor() Renders DropDownList Instead of CheckBox

Question

I'm new from WebForms to MVC 3 and have an issue with the @Html.EditorFor() helper method.

I have a strongly typed view that represents data from a database, and one of the methods is of type bool?. I'd like this to appear as a checkbox, but instead it appears as a dropdownlist with the options "Not Set", "True" and "False".

What is the simplest way to covert this to a regular checkbox?

I understand that I could change the data type to a plain old bool, but this is a large EF entity I'm using and it seems a pain to have to recreate the entire class just for this. I also realize I'll lose the ability to track the "not set" state, but showing a simple checkbox is more important to me.

Answer 1

Use the checkbox helper method instead, @Html.CheckBoxFor()

It's rendering a drop down list as a check box wouldn't be able to provide the value "not set".

Answer 2

Basically, ASP.NET MVC has some default templates (you can read that here).

If you wish, you could add your own EditorTemplate and ASP.NET MVC will use it instead of default. For this you should place a file 'Boolean.{your-view-engine-extension}' (ex.: 'Boolean.aspx') into either ~/Views/ControllerName/EditorTemplates/ or ~/Views/Shared/EditorTemplates/ and override it with your own functionality.

Here is the default editor for Boolean, which can be enhanced by you:

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %>
<script runat="server">
    private List<SelectListItem> TriStateValues {
        get {
            return new List<SelectListItem> {
                new SelectListItem { Text = "Not Set", Value = String.Empty, Selected = !Value.HasValue },
                new SelectListItem { Text = "True", Value = "true", Selected = Value.HasValue && Value.Value },
                new SelectListItem { Text = "False", Value = "false", Selected = Value.HasValue && !Value.Value },
            };
        }
    }
    private bool? Value {
        get {
            if (ViewData.Model == null) {
                return null;
            }
            return Convert.ToBoolean(ViewData.Model, System.Globalization.CultureInfo.InvariantCulture);
        }
    }
</script>
<% if (ViewData.ModelMetadata.IsNullableValueType) { %>
    <%= Html.DropDownList("", TriStateValues, new { @class = "list-box tri-state" }) %>
<% } else { %>
    <%= Html.CheckBox("", Value ?? false, new { @class = "check-box" }) %>
<% } %>