Why use Service.Model from Silverlight for WindowsPhone?

Question

I understood Silverlight was drop by MS. I create my first app permitting to read RSS in WindowsPhone and I need to add a reference to System.ServiceModel.Syndication.dll. In the doc http://msdn.microsoft.com/en-us/library/windowsphone/develop/hh487167(v=vs.105).aspx, I need to find this lib in Microsoft SDKs/Silverlight/v4.0/Libraries/Client/.Why should I do it? Why I can't add directly a lib from the standard .net4?

Can you help me to understand.

[UPDATE] When I add the lib from C:\Program Files (x86)\Microsoft SDKs\Silverlight\v4.0\Libraries\Client\ Visual Studio shows a windows "Adding reference to Windows Phone XNA assembly is safe. However adding reference to a silverlight assembly may lead to unexpexted application behavior. Do you want to continue.

So my assumption is this lib shoudn't be use but I don't find another way. Maybe by add a ref from .Net 4 or 4.5.

Best regards, Alexandre

Answer 1

The Windows Phone 7 SDK was built on top of Silverlight. For Windows Phone 8 this was changed so that there isn't a direct history with Silverlight but it was based on WinRT instead. Lots of functionality was made available to Silverlight controls to support backwards compatibility with apps written for 7.

Because WinRT is not compatible with classes written for the full version of the framework you cannot use these in your Windows Phone apps.

The warning you are getting is just a warning. It's telling you that your doing something that isn't an ideal and so you may have issues. Unfortunately there are no other versions of the SyndicationFeed object available to Windows Phone apps so you'll need to use this library if you want the functionality of SyndicationFeed without recreating it yourself. The good news is that there are no issue with using this class in your app. Just be sure to test carefully, on real devices, if you start to use other functionality from that assembly because, as the warning says: "there may be unexpected behaviour".