Issue upgrading project to target Silverlight 4

[Chris]

Hi,

Some background: Some time ago I inherited maintenance of our Silverlight project, implemented by a developer who has left the company, and I'm not familiar with Silverlight development (I'm perfectly happy making C# changes, but not on the XAML side). I have established that we purchased controls from you in 2008, and from scouring the code I've found reference to usage of RadMenu, RadWrapPanel, RadDockPanel, RadWindow and HierarchicalDataTemplate.

I'm currently looking at moving our codebase to Visual Studio 2010. In the case of this Silverlight/WCF project, I first tried moving everything to .net 4.0 and Silverlight 4, and that was a disaster, so I've taken things step-by-step, resolving individual issues as I encountered them and now have it working perfectly fine on .net 4.0, IIS7 and Silverlight 3.

The problem starts at the point when I change the targeted Silverlight version from 3 to 4. After fixing a few minor reference issues, I now get this exception on instantiating the main window of the application, and have no idea where to start looking to fix it:

System.Windows.Markup.XamlParseException: Set property 'System.Windows.FrameworkElement.Style' threw an exception. [Line: 570 Position: 169] ---> System.Windows.Markup.XamlParseException: Set property 'Telerik.Windows.Controls.ResourceDictionary.MergedDictionaries' threw an exception. [Line: 10 Position: 24] ---> System.Resources.MissingManifestResourceException: A resource with key 'Telerik.Windows.Controls.RadCube' cannot be found in '/Telerik.Windows.Controls.Navigation;component/Themes/Cube.xaml'.
   at Telerik.Windows.Controls.ResourceDictionary.MergeWith(ResourceDictionary dictionary)
   at Telerik.Windows.Controls.ResourceDictionary.OnMergedDictionariesChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
   at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
   at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Telerik.Windows.Controls.ResourceDictionary.SetMergedDictionaries(DependencyObject obj, ResourceDictionary value)
   --- End of inner exception stack trace ---
   at MS.Internal.XcpImports.CreateFromXaml(UnmanagedMemoryStream stream, String sourceAssemblyName, Boolean createNamescope, Boolean requireDefaultNamespace, Boolean allowEventHandlers)
   at System.Windows.Controls.Control.GetBuiltInStyle(IntPtr nativeTarget, IntPtr& nativeStyle)
   --- End of inner exception stack trace ---
   at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
   at XXXXApplication.Views.MainApplication.InitializeComponent()

Any ideas on how to fix this, or are the libraries that we purchased just not going to work in a project targeting Silverlight 4?

It's not important from my point of view that the project uses Silverlight 4, since it's essentially just in maintenance now, but I don't know what the longer-term implications of the application being stuck on Silverlight 3 are.

Thanks,

Chris

[Hristo]

Hi Chris,

You are using a very old version of our controls and this is the main origin of the problems since you cannot use it against Silverlight 4. Since 2008 there are a lot of improvements both for the platform and for RadControls for Silverlight. My best recommendation would be to update your project and take advantage of all newer features and controls.


Best wishes,
Hristo
the Telerik team

[Chris]

I assume we would have to pay for updated controls?

I don't know if we can justify the expense since we don't really need anything else from Silverlight 4, but it might be worth evaluating.

Thanks,

Chris