Is it considered bad practice to have ViewModel objects hold the Dispatcher?
- by stiank81
My WPF application is structured using the MVVM pattern. The ViewModels will communicate asynchronously with a server, and when the requested data is returned a callback in the ViewModel is triggered, and it will do something with this data. This will run on a thread which is not the UI Thread. Sometimes these callbacks involve work that needs to be done on the UI thread, so I need the Dispatcher. This might be things such as:
Adding data to an ObservableCollection
Trigger Prism commands that will set something to be displayed in the GUI
Creating WPF objects of some kind.
I try to avoid the latter, but the two first points here I find to be reasonable things for ViewModels to do. So; is it okay to have ViewModels hold the Dispatcher to be able to Invoke commands for the UI thread? Or is this considered bad practice? And why?