Bubbling Events from UserControl using MVVM in WPF..?

Question

First of all, I want to let everyone know that I'm very new to the MVVM concept, and have looked pretty extensively for some explanation of what I want to do, but to no avail.

In the program I'm working on, I have a UserControl with a few buttons on it, which need to control the navigation of the main window. I have 3 different "pages" I want to be able to switch between in my main window. Instead of pages, I decided (for whatever reason, correct me if this is not the best approach) to use a UserControl for each page, and switch the visibility to the correct one. I need the data to persist while switching, so I don't believe that creating new instances of the Usercontrols will work.

My question is: How can I bubble the events from my "NavBarView" to the main window in a way that will allow me to switch the visibility, but in a MVVM way? I know I may be completely going about this the wrong way, and I'm happy to take any suggestions on a better way of achieving this navigation.

I have to use WPF, so WinForms is not an option. Too much transparency and custom controls for WinForms.

Answer 1

I would make the "NavBar" part of the main window if possible and use that to control the sub controls in the forms. I would be careful nesting User Controls. If you can avoid it I would (key indication is are you going to reuse it somewhere else). I took over a project a while back that had a main window with 3 separate highly coupled user controls that had to all work together and it was a nightmare. The only way I could get it to work somewhat safely was to have them all set their data context to the same view model. If I had to do it from scratch - would have taken a completely different approach with a single view.