How to call Winforms-style Invoke/Delegate from MVVM?

I'm hacking away at some code which seems to have been started, at least in theory, as an MVVM project in Expression Blend, by my predecessor at this company.

I've got a thread running in the background, which is running some operations on items as the开发者_运维百科y happen. In order to prevent any clashes, I've also got that thread running any operations my users call for.

Once those operations are completed, I'd like to bring up a MessageBox to give a summary of the user-initiated operations, but now that they're running off in their own thread, the finishedProcessing event handler is now running on the background thread instead of the interface thread and it's causing my MessageBoxes to appear non-modally.

Back in the WinForms days, I'd have handled that using InvokeRequired, Invoke and a Delegate. I've read that this has been replaced by something called "Dispatcher", but the ViewModel class I'm using doesn't seem to have a Dispatcher object.

The "thisViewModel" class I'm using inherits a class called "WorkspaceViewModel", which inherits "ViewModelBase", both of which look generated to me...

Sorry if all of this is a bit vague, but I didn't write the code. Anyhow, does anyone know where I can link up to this "Dispatcher" from here?

Have a look at this, http://www.codeproject.com/KB/WPF/MessageBoxInMVVM.aspx