How to bind an enumeration to combobox

Question

I would bind the values of an enumeration with a combobox control.

I've written this code:

cboPriorLogicalOperator.DataSource = Enum.GetValues(typeof(MyEnum))
    .Cast<MyEnum>()
    .Select(p => new { Key = (int)p, Value = p.ToString() })
    .ToList();

myComboBox.DisplayMember = "Value";
myComboBox.ValueMember = "Key";

It works well but I wonder if there is a simpler way.

Answer 1

I think your code is beautiful!

The only improvement would be to place the code in an Extension Method.

EDIT:

When I think about it, what you want to do is to use the Enum as in the definition and not an instance of the enum, which is required by extensions methods.

I found this question, which solves it really nicely:

public class SelectList
{
    // Normal SelectList properties/methods go here

    public static SelectList Of<T>()
    {
       Type t = typeof(T);
       if (t.IsEnum)
       {
           var values = from Enum e in Enum.GetValues(t)
                        select new { ID = e, Name = e.ToString() };
           return new SelectList(values, "Id", "Name");
       }
       return null;
    }
}

// called with 
var list = SelectList.Of<Things>();

Only you might want to return a Dictionary<int, string> and not a SelectList, but you get the idea.

EDIT2:

Here we go with a code example that covers the case you are looking at.

public class EnumList
{
    public static IEnumerable<KeyValuePair<T, string>> Of<T>()
    {
        return Enum.GetValues(typeof (T))
            .Cast<T>()
            .Select(p => new KeyValuePair<T, string>(p, p.ToString()))
            .ToList();
    }
}

Or this version perhaps, where the key is an int

public class EnumList
{
    public static IEnumerable<KeyValuePair<int, string>> Of<T>()
    {
        return Enum.GetValues(typeof (T))
            .Cast<T>()
            .Select(p => new KeyValuePair<int, string>(Convert.ToInt32(p), p.ToString()))
            .ToList();
    }
}

Answer 2

Why not to use:

myComboBox.DataSource  = Enum.GetValues(typeof(MyEnum))

?

Answer 3

foreach (int r in Enum.GetValues(typeof(MyEnum))) 
{
     var item = new ListItem(Enum.GetName(typeof(MyEnum), r), r.ToString());
     ddl.Items.Add(item);
}