如何在WPF上为IDataErrorInfo使用异常消息

i was wondering how to best validate some user inputs on the WPF mvvm pattern? I've implemented IDataErrorInfo in my ViewModel. But I don't know how to use this interface with raising an exception. My purpose is to not have any logic in my viewModel. So the validation has to be in the business logic class.i was wondering how to best validate some user