Configuration Value Converter for enum and List<T>

ProductElement3.cs

public class ProductElement : ConfigurationElement
{
  [ConfigurationProperty("types", IsRequired = true)]
  [TypeConverter(typeof(PipeDelimitedFlaggedEnumConverter<ProductTypes>))]
  public ProductTypes Types
  {
    get { return (ProductTypes)this["types"]; }
    set { this["types"] = value; }
  }
}