I have a view model with a DependencyProperty called SelectionValue that is data bound to the SelectedItem property on a ComboBox on my view. I have also implemented IDataErrorInfo on the view model to allow me to provide validation feedback to the user based on their selection. I used to be able to fire an INotifyPropertyChanged event in order to force the ComboBox binding to re-trigger the IDataErrorInfo validation code in my view model, however in the past week or two this seems to have stopped working. The only way I am now able to force the validation check to be re-triggered is to set the SelectionValue property to null and then set it back to it's original value.
Is anyone able to explain why I am seeing this behaviour?
I have noticed that there have been a few Windows updates involving the .NET Framework recently. Could this be a cause of the issue?
Thanks
Shaun