using System; namespace Castle.Components.DictionaryAdapter { [AttributeUsage(AttributeTargets.Property | AttributeTargets.Interface, AllowMultiple = false)] public class NewGuidAttribute : DictionaryBehaviorAttribute, IDictionaryPropertyGetter, IDictionaryBehavior { private static readonly Guid UnassignedGuid = default(Guid); public object GetPropertyValue(IDictionaryAdapter dictionaryAdapter, string key, object storedValue, PropertyDescriptor property, bool ifExists) { if (storedValue == null || storedValue.Equals(UnassignedGuid)) { storedValue = Guid.NewGuid(); property.SetPropertyValue(dictionaryAdapter, key, ref storedValue, dictionaryAdapter.This.Descriptor); } return storedValue; } } }