WPF: Cancel a user selection in a databound ListBox?

Question

How do I cancel a user selection in a databound WPF ListBox? The source property is set correctly, but the ListBox selection is out of sync.

I have an MVVM app that

Answer 1

Bind ListBox's property: IsEnabled="{Binding Path=Valid, Mode=OneWay}" where Valid is the view-model property with the validation algoritm. Other solutions look too far-fetched in my eyes.

When the disabled appearance is not allowed, a style could help out, but probably the disabled style is ok because changing the selection is not allowed.

Maybe in .NET version 4.5 INotifyDataErrorInfo helps, I dont'know.