I have a XDG set out with some standard fields, and I programmatically add hundreds or thousands of fields during runtime. XDG handles this very well with virtualization and etc. However, one problem is that it is not as simple as specifying a BindingPath because these values don't come from properties of the object, I have to manually specific the binding on each cell in the cellsinviewchanged event. I have tried binding to CVP's value, but this did not work, apparently the Value is not the actual value, but a wrapping object. Instead, I used a binding on the ValueEditor.Value property. This seems to have the desired effect. 

However, one problem with this approach is that I *must* leave virtualization on for reasonable performance, but when editors are recycled, they assign back to my objects the value NULL. So when I am scrolling the datagrid, when cells are scrolled out of view, they apply null to all nullable objects that I've bound. This is a problem for things like strings where I want to be able to assign null, just not when they scroll out of view.

For my scenario, is there a best practices approach to solving the problem?