Creating Navigation Structures in Silverlight (Silverlight TV #38)

Good Tutorial and clearly explained

Althou I felt familiar with the navigation framework I just picked up some parts new to me. Thanks for this great show!

Thank you David and John for another Excellent TV Episode.

SLTV Rocks !!!

KRK

Excellent video, thanks for posting it.

Question about the INavigationContentLoader.  Can more than one custom ContentLoader be specified in Xaml where the Frame is defined? I think I recall an error indicating that the <navigation:Frame.ContentLoader> can only be set once.  Surly there is a way to use multiple content loaders; Errors, authentication...etc.

thanks again,

Greg

Greg,

It's not possible "by default".  However, take a look at some of my ContentLoader posts on my blog.  I have ContentLoaders that delegate to other ContentLoaders, allowing them to be chained together to "decorate" the loading behavior with error handling, authentication, etc.  Thankfully, these ContentLoaders compose reasonably well, so you can really create some expressive declarative definitions of navigation behavior.

ContentLoader-related posts

Let me know if you have any questions!  I'll be happy to try to help!

-David Poll

One thing for the next video would be nice to cover, is when a page is loaded in a frame and then within that page, there might be links to load other pages into the frame. Another words, instead of from outside of the frame to load a page, but rather a loaded page can load another page to replace itself in the frame.

Secondly, is ContentLoader covered in WP7?

Hello, great article but in SL4 i can see many article with design pattern mvvm which a best practise, why you don't use it ?

Great video. It's really useful.

Chris,

It's certainly possible to use MVVM with all of this -- the main reason it's not used here was because of time/simplicity constraints on the quick demo.

-David

Ben,

Thanks for the suggestion.  To answer your questions (since I don't know all of what Karl will go into in the next video):

Links within a page -- this is actually quite straightforward.  HyperlinkButton (and Hyperlink for use in RichTextBox) searches its neighbors and up its visual tree for an INavigate (which Frame implements).  If no TargetName is given, it will navigate the first INavigate it encounters.  As a result, within a page, you just need to use a HyperlinkButton with no TargetName set (e.g. <HyperlinkButton NavigateUri="/Views/SomePage.xaml" Content="Navigate to some page" />), and clicking this will navigate the frame to another page.  If you need to accomplish this in code, within the page you can write this.NavigationService.Navigate(new Uri("/Views/SomePage.xaml", UriKind.Relative)).

As for WP7 and ContentLoaders, since WP7 is based on Silverlight 3 and ContentLoaders were not introduced until Silverlight 4, as far as I know WP7 does not support ContentLoaders.

-David

David, it's always nice to see you!~

Thanks for the reply. I brought up those points for some of the new comers, but I wasn't aware of WP7 missing ContentLoaders, since they always say WP7 is a "Superset" of SL3. So it's kind of a mystery what "Superset" means

Man WP7 V2 better be alligning with SL5 to have full support for LINQ and some other important parts.

Aren't you going to do part 2?

David,

I am still trying to figure out how best to use the navigation framework with Prism and the idea of Regions which provide place holders for views that reside within discrete prism modules. Have you any thoughts on the subject

regards

Shayzer