http://ayende.comAyende @ RahienCopyright (C) Ayende Rahien 2004 - 2021 (c) 202660I have a similar problem with base classes and proxies, but mine also involves sublassing with discriminators. The setup is following: - base class A, has Lazy=true, subclasses A1, A2 & A3 (table-per-class pattern - one table with columns for all class tree), discriminator field named e.g. "ASubClass" - class B has some property of type A (e.g. "myA") Now, I am trying to do the following: B myB = B.FindOne(.....); A myA = B.myA; if (myA.ASubClass == "1") //1 is discriminator value in subclass A1 { //discriminator says it is an A1! A1 myA1 = (A1)myA; //Error! } Now, the line marked as Error, yields an "cannot cast NhibernateProxy to A1" exception - similarly to what you wrote in this post, the actual "myA" is an NHibernateProxy subclassing class A. However, it should rather be an proxy subclass of A1... Frankly speaking, I don't know how to go around this... How to cast the lazy initialized object to its subclass? I do not fully understand the solution that you gave here, Ayende :( http://ayende.com/3691/how-nhibernate-forced-me-to-oo-design#comment2http://ayende.com/3691/how-nhibernate-forced-me-to-oo-design#comment2Fri, 21 Nov 2008 15:50:11 GMTHeh, that should read "Tell, don't ask" :) I wonder, what DisplayInformation looks like. Do you use it like: if(info.IsImage) { ... } else { ... } http://ayende.com/3691/how-nhibernate-forced-me-to-oo-design#comment1http://ayende.com/3691/how-nhibernate-forced-me-to-oo-design#comment1Wed, 12 Nov 2008 18:48:08 GMT