How can I use XPathSelectElement in a portable class library? When I try to include System.Xml.XPath assembly in the project, I get the following error:
The type 'System.Xml.Linq.XElement' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Xml.Linq, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.
My portable class libraries already have a reference to System.Xml.Linq.
Unfortunately, MSDN is showing that, as of .NET 4.5, these extension methods are not supported in Portable Class Libraries. If they were supported, they would display a 
image. However, it looks like Microsoft did provide a Nuget package that provides at least some of the functionality in the System.Xml.XPath namespace.
Because XPathSelectElement is declared in System.Xml.Linq.dll, you should also reference it.
More details can be found here.
