Method to compress XAML: Removes comments, whitespace, and mc:Ignorable components

XamlMinify.cs

        static string Minimize(XDocument document)
        {
            //take out the comments
            document.DescendantNodes().OfType<XComment>().Remove();

            //take out the mc:ignorables
            XNamespace mc = "http://schemas.openxmlformats.org/markup-compatibility/2006";
            var ignorable = document.Root.Attribute(mc + "Ignorable");
            if (ignorable != null)
            {
                string[] ignorablePrefixes = ignorable.Value.Split(' ');

                var prefixNamespaces = document
                    .Root
                    .Attributes()
                    .Where(a => a.IsNamespaceDeclaration)
                    .GroupBy(a => a.Name.Namespace == XNamespace.None ? String.Empty : a.Name.LocalName, a => XNamespace.Get(a.Value))
                    .ToDictionary(g => g.Key, g => g.First());

                List<string> ignorableNamespaces = ignorablePrefixes.Select(x => prefixNamespaces[x].NamespaceName).ToList();

                //remove elements
                document.Descendants()
                    .Where(x => ignorableNamespaces.Contains(x.Name.NamespaceName))
                    .Remove();

                //remove attributes
                document.Descendants()
                    .SelectMany(x => x.Attributes())
                    .OfType<XAttribute>()
                    .Where(x => ignorableNamespaces.Contains(x.Name.NamespaceName))
                    .Remove();
            }

            //create the tightest XmlWriterSettings imaginable
            var settings = new XmlWriterSettings
                           {
                               NamespaceHandling = NamespaceHandling.OmitDuplicates, 
                               Indent = false, 
                               NewLineChars = "",
                               NewLineHandling = NewLineHandling.Replace,
                           };

            //save it into a stringbuilder
            StringBuilder output = new StringBuilder();
            var writer = XmlWriter.Create(output, settings);
            document.Save(writer);
            writer.Flush();

            //get rid of the silly space at the end of all self-closing tags
            output.Replace("\" />", "\"/>");
            return output.ToString();
        }

Very handy!