How to get pre-change Object state from a Class Extension change event in ArcObjects?

Question

I have an Esri based system with a class extension registered for the feature classes. This extension implements IObjectClassEvents, and handles OnChange. I get passed the modified object, but after the change was made (e.g. an object was moved from within ArcMap).

However, I also need to know the state of the IObject before the change was made. How do I go about that?

Answer 1

Try IFeatureChanges (for features) or more generally, IRowChanges for either a row or a feature.