Question

I have the following xml, from which I am trying to remove all “xmlns” attributes using LINQ to XML:

    <Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
      <StackPanel>
        <LinearLayout xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly"/>                
        <TextView xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly">

  </StackPanel>
</Window>

The following code is used. It hits “attributesToRemove.Remove()” for each “xmlns” attribute in the document. But when I save the document, I still have the original XML. Any idea, what is the problem might be?

 var sr = new StringReader(richTextBoxOriginalXml.Text);
            XDocument xdoc = XDocument.Load(sr);            
            foreach(var node in xdoc.Descendants().ToList())
            {
                var xmlns = node.Attributes().FirstOrDefault(a => a.Name == "xmlns");
                if (xmlns !=null)
                {
                    var attributesToRemove = node.Attributes("xmlns").ToList();
                    attributesToRemove.Remove();
                }
            }

            var writer = new StringWriter();
            var xmlWriter = new XmlTextWriter(writer);
            xmlWriter.Formatting = Formatting.Indented;
            xdoc.WriteTo(xmlWriter);
            richTextBoxTransformed.Text = writer.GetStringBuilder().ToString();

Answer 1

Like Marc Gravell pointed out before I posted, xmlns attribute (unqualified) is not an attribute as such, it’s considered part of the name of the element.

<StackPanel xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
    <LinearLayout xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly" />
    <TextView xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly" />
</StackPanel>   

StackPanel tag has no attributes here. It’s name, however, is {http://schemas.microsoft.com/winfx/2006/xaml/presentation}StackPanel.

Name.Namespace is {http://schemas.microsoft.com/winfx/2006/xaml/presentation} (XNamespace type) and Name.LocalName == "StackPanel".

Thus you need to effectively rename the element. It should work.

Oversimplified (but compilable) program:

using System;
using System.Linq;
using System.Xml.Linq;

namespace ConsoleApplication
{
    class Program
    {          
        static void Main(string[] args)
        {
            var raw = @"<Window xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""
            xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml"">
      <StackPanel>
        <LinearLayout xmlns=""clr-namespace:AndroidAssembly;assembly=AndroidAssembly""/>                
        <TextView xmlns=""clr-namespace:AndroidAssembly;assembly=AndroidAssembly""/>    
  </StackPanel>
</Window>";

            var xml = XElement.Parse(raw);
            var descendants = xml.Descendants().ToArray();
            var stackPanel = descendants.First();
            Console.WriteLine(stackPanel.ToString());

            Console.WriteLine("==================================");
            stackPanel.Name = stackPanel.Name.LocalName; // stripping the namespace off
            Console.WriteLine(stackPanel.ToString());

            Console.ReadLine();
        }
    }
}

Output:

<StackPanel xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
  <LinearLayout xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly" />
  <TextView xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly" />
</StackPanel>
==================================
<StackPanel>
  <LinearLayout xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly" />
  <TextView xmlns="clr-namespace:AndroidAssembly;assembly=AndroidAssembly" />
</StackPanel>

The difference in the StackPanel element is easy to notice…

By the way, there is a typo in the XML you posted (TextView tag is not closed), but I can’t edit it out – edits must be at least 6 characters long 🙂 (Why 6?)