任务或对话框的Presentation- / ViewModel如何？

I'm trying to move to a Model/ViewModel/View architecture and got stuck when trying to push selection dialogs to this pattern. I'd like to separate retrieving a list of choices (business/presentation logic) and the actual displaying/choosing mechanism (view) to re-use the former with different views (e.g. ComboBox vs. modal dialog).I'm trying to move to a Model/ViewModel/View ar