WPF dynamic content tabs NOT suitable substitute for MDI user interface

Question

So I have this old PowerBuilder MDI application (medium enterprise app with about 40 windows), and I'm embarking on designing my very first WPF MVVM C# application to replace the aging PowerBuilder app. I've got plenty of C# & .NET experience, but this is my first WPF & MVVM app.

After reading many forum postings after searching for WPF & MDI alternative, I've come to the conclusion that the MDI isn't supported, and that the most commonly proposed substitute is to use the TabControl and dynamically generate the content of each tab page upon demand using a WPF User Control. I had initially been sold on this, and was actually excited by my initial prototype interface with a tabbed Ribbon bar at the top of the app, and the TabControl with the tabs of the app underneath that. However, I have hit a BIG brick wall.

Take a look at the following screen shot of one of the central multi-tab windows from my old application: http://www.creativedatatech.com/downloads/screenshot.jpg

As you can see, the app has a toolbar across the top and the left side, and the example MDI child window (Case Edit Window) that is open has a LOT of tab pages (18 of them), and the users really like being able to quickly click on a tab page to get directly to that information to work on it. Moreover, the users have grown accustomed to being able to open multiple Cases at once and either put them side by side (large monitors), or flip back and forth, possibly copying & pasting between them.

The problem here is that I cannot envision how I am going to incorporate all this multi-tab user experience for the Case Edit Window into a single tab of the top level WPF TabControl. Will the users end up seeing a row of tabs for the WPF TabControl, with one tab for each Case Edit Window that is open, and then inside each "Case Edit" tab page, a further nested set of 18 tab pages?? This seems confusing and a big mess of nested tabs. Add to that the tabs of the Ribbon control at the top of the app, and I think my users will be running after me to lynch me!

After investing two straight weeks reading up on WPF and MVVM, I am left with the sinking feeling that WPF really isn't going to fly well for enterprise apps such as mine. Surely this can't be true! Does anyone have any comments on how I should go about shaping this app to accomplish what I'm trying to do here?
I've already looked at WPF "pages", but I can't have the users serially navigate through all the individual pages to get to the content that they need to work on, and they need to be able to quickly (and visually) navigate to the Case Edit Window content that they need.

Answer 1

We had this same dilemma, we decided on screen tabs at the bottom with tabs that relate to that screen at the top - and contextual ribbon items.

The tabs in the screens actually just scroll the window to the desired point so all information is sectioned off and available on each screen by scrolling or clicking the tab at the top.

Looks like this

Answer 2

I think your problem is not so much WPF, but rather that GUI paradigms have moved away from the MDI that your current app uses. There is nothing stopping you implementing MDI in WPF, but what would be the point if your app ends up looking like it does now?

You really need to think about how to layout your app in a modern way. Perhaps you could keep your tabs for the different cases, but replace the multiple tabs in each child window with a master/detail view, much like Dev Studio does for its Options dialog?