Almost all articles on WPF and validation focus first on ValidationRules, and then continue telling you why IDataErrorInfo is better. A few go on and show you how to combine IDataErrorInfo with DataAnnotations. While these last two are definitely good options, they’re a little heavy for a very simple application. In my case: call a server, show the data (about 20 textboxes), send back to the server. Nothing fancy, I’m even databinding to my datacontract (gasp!), although I’m sending back