New Post: How to detect Clean, Dirty, Invalid status of View (not ViewModel)

I am failing to explain the issue, please consider this image:



The key thing is to understand how the idea of "Dirty" and "Valid" is handled during an edit-in-progress
with a TextBox with UpdateSourceTrigger = LostFocus (the default)

The behavior on the left is expected, but WPF apps tend to the behavior on the right (due to a design flaw in the Binding / BindingGroup classes)

WPF apps only correctly activate the buttons AFTER LostFocus

but that is confusing for users who expect things to work normally