Question

In my MVVM based application I need to validate fields in a data entry from. If possible, I would like to use the standard WPF validation binding with ErrorTemplates.

However I would like the execution of the validation logic to be completely driven/triggered by the ViewModel (push to the View, not pull by the View) for the following reasons:

1. It must work asynchronously because validation logic might take a while to execute.
2. I need to be more deterministic and fine grained when validation logic is to be executed (e.g. only after the user clicks “Apply” or when the internal state changed in a way that entries suddenly become invalid)

I know Silverlight has INotifyDataErrorInfo which was introduced for exactly this purpose, but WPF doesn’t. How can I still have my validation logic exectuted deterministically and asynchronously?

Answer 1

I posted an answer on your other question that apparently answered this one too.

Create a visualtree off of a control template in code