How to use a custom UITypeEditor for an enum?

Question

I wrote a custom UITypeEditor for my type Smiley per MSDN's walkthrough http://msdn.microsoft.com/en-us/library/ms171840.aspx

When the user clicks the ellipsis, my UITypeEditor will launch a modal dialog box.

public class SmileyEditor : UITypeEditor
{
    public override UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
    {
        return UITypeEditorEditStyle.Modal;
    }

After MUCH PAIN I found it works if my type is a Class, but not if it's an enum. What's going on?

    [Editor(typeof(SmileyEditor), typeof(System.Drawing.Design.UITypeEditor))]
    public Smiley face { get; set; }

If the type Smiley is an enum, then the property grid doesn't show the ellipsis button, just a drop down. Why?

Answer 1

Apparently when a system type editor exists, PropertyGrid prefers it over one's custom editor. A workaround is to annotate your type with a TypeConvertorAttribute, referencing a TypeConvertor that overrides the method GetStandardValuesSupported. See https://stackoverflow.com/a/4067173/284795