Question

I am trying to dynamically fill a second panorama page based on what item was selected from the home application screen.

On the application’s first start screen there is a listbox if items each with text. If a user taps on an item with text “foobar” a template page should load and the title of the template page should be set to “foobar” and this second panorama page should know that it’s data should be related to “foobar”.

Is there anyway to do this?

I currently have my MainPage navigate to a new page (DynamicPage.xaml). This navigation is triggered when a ListBox_SelectionChanged event occurs. I have the title text of the DynampicPage.xaml Binding to a TitleText variable that is located in MainPage.xaml.cs. However, when I do this the title of DynamicPage.xaml is ever only set to my initialization value for the titleText variable even though I am updating this variable right before I navigate to the page.

If anyone can provide some help I would be very grateful as I am just a beginner on the WP7 platform. Thanks!

Answer 1

The Binding you’re using for the title is only going to update if the TitleText property is a dependency property or if your MainPage is implementing the INotifyPropertyChanged interface so your class can notify the UI when one of its properties changed.

http://windowsphonegeek.com/articles/All-about-Dependency-Properties-in-Silverlight-for-WP7

http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged(v=vs.95).aspx

But I think this is not the best way for you to achieve this. For now a much better way is to store your data somewhere in a static class, in the main page’s constructor load these data into the listbox, and when the user selected an item, navigate the user to the second page like this:

NavigationService.Navigate(new Uri("/DynamicPage.xaml?Item=" + selectedItem.Id, UriKind.Relative));

When you navigate like this a new instance of DynamicPage is created, and in the OnNavigatedTo method you can access the navigation parameters and populate your page with the selected data. For example:

<controls:Panorama x:Name="MyPanorama" Title="TitleHere">...</controls:Panorama>

Item selectedItem = StaticData.GetItem(NavigationContext.QueryString["Item"]);
MyPanorama.Title = selectedItem.Name.ToUpper();
Description.Text = selectedItem.Description;

This way you can use secondary tiles and toast notifications to directly point to a specific content in your application.

If you’re getting to understand the navigation you should definitely use the pattern called Model-View-ViewModel which is about to solve these problems mostly with bindings, but trust me, probably this is the easier way for now.