Silverlight4 disable textbox required validation when form loads with initial value (null)

Question

I am trying to implement validation using IDataErrorInfo or INotifyDataErrorInfo but either way I am struggling to make it work only once user start entering data or clicking save button. Since I am using MVVM, I am setting my view's datacontext to ViewModel and my ViewModel is implementing IDataErrorInfo / INotifyDataErrorInfo. I need to make sure validation happens but not when form loads up. Anyone has got any suggestion how I can implement?

Thanks

Answer 1

Add IsDirty property to your business object. Return no error when IsDirty == false.