How to get the values of an enum into a SelectList

Question

Imagine I have an enumeration such as this (just as an example):

public enum Direction{
    Horizontal = 0,
    Vertical = 1,
    Diagonal = 2
}

Answer 1

It's been awhile since I've had to do this, but I think this should work.

var directions = from Direction d in Enum.GetValues(typeof(Direction))
           select new { ID = (int)d, Name = d.ToString() };
return new SelectList(directions , "ID", "Name", someSelectedValue);

Answer 2

I had many enum Selectlists and, after much hunting and sifting, found that making a generic helper worked best for me. It returns the index or descriptor as the Selectlist value, and the Description as the Selectlist text:

Enum:

public enum Your_Enum
{
    [Description("Description 1")]
    item_one,
    [Description("Description 2")]
    item_two
}

Helper:

public static class Selectlists
{
    public static SelectList EnumSelectlist<TEnum>(bool indexed = false) where TEnum : struct
    {
        return new SelectList(Enum.GetValues(typeof(TEnum)).Cast<TEnum>().Select(item => new SelectListItem
        {
            Text = GetEnumDescription(item as Enum),
            Value = indexed ? Convert.ToInt32(item).ToString() : item.ToString()
        }).ToList(), "Value", "Text");
    }

    // NOTE: returns Descriptor if there is no Description
    private static string GetEnumDescription(Enum value)
    {
        FieldInfo fi = value.GetType().GetField(value.ToString());
        DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
        if (attributes != null && attributes.Length > 0)
            return attributes[0].Description;
        else
            return value.ToString();
    }
}

Usage: Set parameter to 'true' for indices as value:

var descriptorsAsValue = Selectlists.EnumSelectlist<Your_Enum>();
var indicesAsValue = Selectlists.EnumSelectlist<Your_Enum>(true);

Answer 3

There is a new feature in ASP.NET MVC 5.1 for this.

http://www.asp.net/mvc/overview/releases/mvc51-release-notes#Enum

@Html.EnumDropDownListFor(model => model.Direction)

Answer 4

Or:

foreach (string item in Enum.GetNames(typeof(MyEnum)))
{
    myDropDownList.Items.Add(new ListItem(item, ((int)((MyEnum)Enum.Parse(typeof(MyEnum), item))).ToString()));
}

Answer 5

In ASP.NET Core MVC this is done with tag helpers.

<select asp-items="Html.GetEnumSelectList<Direction>()"></select>

Answer 6

To get the value of an enum you need to cast the enum to its underlying type:

Value = ((int)i).ToString();