When the customer tabs, the focus is going to the next element on the page behind/under the Dialog. That can happen only if the input behind the Dialog has its TabIndex set.

Currently using VisibleChanged event, I can tell when a dialog is closed.  However, if you have a component inside the dialog and trying to reference that component before the dialog is fully rendered you get a null reference exception.

What I am proposing is adding a new event or extending VisibleChanged so that we know when the dialog has been initialized.