Personally, I have never use Prism. However, based on what I read here, using UXWindow controls as the region view holder is quite viable.

Chris,

In case you have not aware, ClientUI already includes built-in application framework which makes composite application development in Silverlight so easy and straightforward.

Rather than forcing developers to learn dozens of interfaces and attributes to satisfy, our app framework lets you simply point to the XAP that contains the UXWindow you want to inject. The app framework even includes built-in loading management and complete app lifecycle for externaly loaded application packages. I recommend you to read further on Application Framework Overview then follow the links in the next steps.

To learn more about many of the powerful libraries in ClientUI, see ClientUI Learning Guide and Resources.

Hope this helps,
Jimmy

Thanks Jimmy.  I am aware of the application framework, and it looks good.  If I didn't already have a lot of infrastructure built in order to use Prism, I would consider it.  But I don't want to go back and rewire my platform to take advantage of the framework. 

Given that, here is what I'm doing...

I'm using the UXDesktop in conjuction with the UXDesktopDock (a.k.a. Task Bar).  I will have a "Start Menu" UXDockButton that will serve as a Prism Region.  Prism will inject the apps that my platform will provide into the "Start Menu" region.  I plan to have a DesktopManager that will handle the "Start Menu" commands to launch apps.  When an app is launched, I want to add an "Instance Button" to the UXDesktopDock that will let the user know that app has at least one instance opened.  If an app is launched with more than one instance, then the DesktopManager will add that new instance to the "Instance Button" on the task bar.  The goal is to have the task bar work like the Windows 7 task bar.  I want the users to be able to "Pin" apps to it from the start menu by dragging a copy of the button down to the task bar.  And I want them to be able to see their app instances in the task bar grouped by app. 

Does this sound feasible?  Can you see any gotchas before I head down this road?

Chris,

Thanks for sharing more information about the scenarios that you're trying to achieve.

We've exactly the same thought with you when our team designed the UXDesktopDock - something that behaves like a Windows 7 taskbar. However, the UXDesktopDock in this release resembles more to the Apple's Dock behaviors and functionality, which is geared toward simplicity and ease-of-use.

I'm pretty sure that the "instance button" that grouped by app, and "multiple groups" within an "instance button" should be feasible to be done through customizations and events handling. You can eventually use the stack menu capability to simulate the "multiple groups" when hover on one of the instance button.

And yes, you can also drag something and drop it into the button at the task bar, then do your own logic to process the drop event, i.e, add the dropped item as a stack menu item. However, this will require you to really master the drag-drop concept in our ClientUI library. You can see that we already introduce a powerful "Transformable UI" concept where an item can have multiple UI representation according to where it's dropped. I suggest you to read Drag-drop Framework Overview to learn further.

Things that I'm not sure is how far you want to take your application to. I.e, what would you do to indicate a pinned application? That would require you to customize the control completely to achieve the desired behaviors/features.

The other possibility is that, if the market demand is decent enough, it might be possible for us to look deeper into this particular behavior and wrap them up to a specialized Windows 7 task bar control. This might cover the stuff such as built-in multiple group support, preview support, application pinning support and more.

Hope this helps,
Jimmy