MVC EditorTemplate for Nullable Booleans

Boolean.cshtml

@model bool?

@if (ViewData.ModelMetadata.IsNullableValueType) {
    var items = new[]
    {
        new SelectListItem { Value = "", Text = "N/A" },
        new SelectListItem { Value = "true", Text = "Yes" },
        new SelectListItem { Value = "false", Text = "No" }
    };
    @Html.DropDownList("", new SelectList(items, "Value", "Text", Model.HasValue ? (Model.Value ? "true" : "false") : ""))
} else {
    @Html.CheckBox(string.Empty, Model.GetValueOrDefault(false))
}