DialogHost doesn't return current value when dialog is accepted from keyboard.

DialogHost doesn't return current value when dialog is accepted from keyboard.

MaterialDesignThemes v. 4.0.0

Repository with example: https://github.com/lszczygielek/MaterialDesignInXamlToolkit-DialogHost-Focus

@Keboo wrote about it on Gitter:

I wrote a small test to also show the issue here. I did write a little UI test to reproduce the issue as well: https://github.com/Keboo/MaterialDesignInXamlToolkit/tree/dialogHostDoesNotUpdate
If anyone wants to have a go at addressing it that would be a good start. I spent a little time looking at it, and it seems like it may be a little difficult with timing to address it within the dialog host as you need to trigger the lost focus event and wait for the binding to update. This may end up being something that needs to be addressed outside of this library.
It also appears this is somewhat expected as several other people have run into similar use cases. https://www.thomasclaudiushuber.com/2008/05/02/lostfocus-textbox-vs-buttons-isdefault-property/

Inizia con l’esempio DialogHost-Focus collegato e il test UI nel branch dialogHostDoesNotUpdate per riprodurre l’accettazione tramite tastiera in MaterialDesignThemes 4.0.0. Traccia quindi la gestione del focus e degli aggiornamenti del binding da parte di DialogHost, poi verifica che l’accettazione della finestra di dialogo restituisca il valore corrente mostrato nel controllo.