Multi-page/user control Silverlight application

Question

I'm starting a project which will contain multiple pages tabs style. Ie you have a footer of the application and it's header. Header contains buttons that load different User Controls in the center of the app. I know how to swap user controls and show one or another, but, what concerns me are events from hidden controls and UI updates.

I was thinking about creating UserControls to represent each page. One would contain list of files available for download, another would contain UI of the download manager that would show end user progress of download.

In order for some page/control, that is not currently showing, to throw events, its instance need to be present. What would happen with UI updates in this case? Consider user selected files to download and added them to the download manager. Download manager is currently in the "background", basically, it's UI doesn't exist (instance of the UserControl exists though). I presume that every attempt to update the UI will end up with an error?

Or, am I over-thinking this? Now, that's all a theory at the moment, I didn't yet code a single line of code for this project because I wanted to consult with someone and start from the right foot.

Thank you in advance.

PS Or may be use tab control...

Answer 1

If I understand you correctly, you are not loading/unloading the usercontrols, but merely showing/hiding the usercontrols. Updating the UI should not cause an error in this case. What you need to the design and implement is a number of events that the container will subscribe to. The container should then trigger funtion calls to the correct usercontrol that needs to be updated. But, as you state I would prefer to use a tab control. But, the event part is still the same.