Exclude/Remove Value from MVC 5.1 EnumDropDownListFor

Question

I have a list of enums that I am using for a user management page. I\'m using the new HtmlHelper in MVC 5.1 that allows me to create a dropdown list for Enum values. I now h

Answer 1

Modified from @dav_i's answer.

This is not perfect, but it is what I am using. Below is an extension to HtmlHelper. The extension method will look like EnumDropDownListFor from ASP.NET, and use DisplayAttribute if there is any applied to the Enum value.

/// 

/// Returns an HTML select element for each value in the enumeration that is
/// represented by the specified expression and predicate.
/// 
/// The type of the model.
/// The type of the value.
/// The HTML helper instance that this method extends.
/// An expression that identifies the object that contains the properties to display.
/// The text for a default empty item. This parameter can be null.
/// A  to filter the items in the enums.
/// An object that contains the HTML attributes to set for the element.
/// An HTML select element for each value in the enumeration that is represented by the expression and the predicate.
/// If expression is null.
/// If TEnum is not Enum Type.
public static MvcHtmlString EnumDropDownListFor(this HtmlHelper htmlHelper, Expression> expression, Func predicate, string optionLabel, object htmlAttributes) where TEnum : struct, IConvertible
{
    if (expression == null)
    {
        throw new ArgumentNullException("expression");
    }

    if (!typeof(TEnum).IsEnum)
    {
        throw new ArgumentException("TEnum");
    }

    ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
    IList selectList = Enum.GetValues(typeof(TEnum))
            .Cast()
            .Where(e => predicate(e))
            .Select(e => new SelectListItem
                {
                    Value = Convert.ToUInt64(e).ToString(),
                    Text = ((Enum)(object)e).GetDisplayName(),
                }).ToList();
    if (!string.IsNullOrEmpty(optionLabel)) {
        selectList.Insert(0, new SelectListItem {
            Text = optionLabel,
        });
    }

    return htmlHelper.DropDownListFor(expression, selectList, htmlAttributes);
}

/// 

/// Gets the name in  of the Enum.
/// 
/// A  that the method is extended to.
/// A name string in the  of the Enum.
public static string GetDisplayName(this Enum enumeration)
{
    Type enumType = enumeration.GetType();
    string enumName = Enum.GetName(enumType, enumeration);
    string displayName = enumName;
    try
    {
        MemberInfo member = enumType.GetMember(enumName)[0];

        object[] attributes = member.GetCustomAttributes(typeof(DisplayAttribute), false);
        DisplayAttribute attribute = (DisplayAttribute)attributes[0];
        displayName = attribute.Name;

        if (attribute.ResourceType != null)
    {
            displayName = attribute.GetName();
        }
    }
    catch { }
    return displayName;
}

For example:

@Html.EnumDropDownListFor(
    model => model.UserStatus,
    (userStatus) => { return userStatus != UserStatus.Active; },
    null,
    htmlAttributes: new { @class = "form-control" });

This will create a Enum dropdown list without the the option of Active.