public static void Main()
<ProductId xsi:nil=""true"" ></ProductId>
<ProductName>Toys</ProductName>
<Description xsi:nil=""true"" ></Description>
<Category xsi:nil=""true"" ></Category>
<Weight xsi:nil=""true"" ></Weight>
<Price xsi:nil=""true"" ></Price>
var root = @"<root xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"">" + xml + "</root>";
var element = XElement.Parse(root);
var productName = (string) element.Element("ProductName");
Console.WriteLine(productName);