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XML adding "ns0" prefix to new XML doc

I am creating a somewhat complex XML file and I need to include the "ns0" prefix to each XmlElement.
Here are the opening lines of code:
var asnFile = new XmlDocument();
var dec = asnFile.CreateXmlDeclaration("1.0", "UTF-8",null);
asnFile.AppendChild(dec);
var advancedShippingNoticesNode = asnFile.CreateElement("AdvancedShippingNotices");
var advancedShippingNoticesNodeAttr = asnFile.CreateAttribute("xmlns");
advancedShippingNoticesNodeAttr.Value = "http://www.testschema.com/schema/AdvancedShippingNotices.xsd";
advancedShippingNoticesNode.Attributes.Append(advancedShippingNoticesNodeAttr);
asnFile.AppendChild(advancedShippingNoticesNode);
var asnIdNode = asnFile.CreateElement("ASNID");
asnIdNode.InnerText = "TestASN";
advancedShippingNoticesNode.AppendChild(asnIdNode);
I have tried adding a prefix in the following way but the prefix never shows up when opening the saved XML file.
advancedShippingNoticesNode.Prefix = "ns0";
I read here that I'm not able to add a prefix, but since I am creating the XmlDocument on the fly and not loading it from an existing file, I feel like this doesn't apply to my case.
I did try the sample solution in the question/answer linked above, but this XmlDocument has so much nesting that it's hard for me to translate that solution into a working solution for myself. I also feel like that is far too complex just to add a prefix.
Is there a simple way to add a prefix to a new XmlDocument?

Deserialize on the fly, or LINQ to XML

Working with C# Visual Studio 2008, MVC1.
I'm creating an xml file by fetching one from a WebService and adding some nodes to it. Now I wanted to deserialize it to a class which is the model used to strongtyped the View.
First of all, I'm facing problems to achieve that without storing the xml in the filesystem cause I don't know how this serialize and deserialize work. I guess there's a way and it's a matter of time.
But, searching for the previous in the web I came accross LINQ to XML and now I doubt whether is better to use it.
The xml would be formed by some clients details, and basically I will use all of them.
Any hint?
Thanks!!

You can save a XElement to and from a MemoryStream (no need to save it to a file stream)
MemoryStream ms = new MemoryStream();
XmlWriter xw = XmlWriter.Create(ms);
document.Save(xw);
xw.Flush();
Then if you reset the position back to 0 you can deserialize it using the DataContractSerializer.
ms.Position = 0;
DataContractSerializer serializer = new DataContractSerializer(typeof(Model));
Model model = (model) serializer.ReadObject(ms);
There are other options for how serialization works, so if this is not what you have, let me know what you are using and I will help.

try this:
XmlSerializer xmls = new XmlSerializer(typeof(XElement));
FileStream FStream;
try
{
FStream = new FileStream(doctorsPath, FileMode.Open);
_Doctors = (XElement)xmls.Deserialize(FStream); FStream.Close();
FStream = new FileStream(patientsPath, FileMode.Open);
_Patients = (XElement)xmls.Deserialize(FStream)
FStream.Close();
FStream = new FileStream(treatmentsPath, FileMode.Open);
_Treatments = (XElement)xmls.Deserialize(FStream);
FStream.Close();
}
catch
{ }
This will load all of the XML files into our XElement variables. The try – catch block is a form of exception handling that ensures that if one of the functions in the try block throws an exception, the program will jump to the catch section where nothing will happen. When working with files, especially reading files, it is a good idea to work with try – catch.

LINQ to XML is an excellent feature. You can always rely on that. You don't need to write or read or data from file. You can specify either string or stream to the XDocument
There are enough ways to load an XML element to the XDocument object. See the appropriate Load functions. Once you load the content, you can easily add/remove the elements and later you can save to disk if you want.

Read entire elements from an XML network stream

I am writing a network server in C# .NET 4.0. There is a network TCP/IP connection over which I can receive complete XML elements. They arrive regularly and I need to process them immediately. Each XML element is a complete XML document in itself, so it has an opening element, several sub-nodes and a closing element. There is no single root element for the entire stream. So when I open the connection, what I get is like this:
<status>
<x>123</x>
<y>456</y>
</status>
Then some time later it continues:
<status>
<x>234</x>
<y>567</y>
</status>
And so on. I need a way to read the complete XML string until a status element is complete. I don't want to do that with plain text reading methods because I don't know in what formatting the data arrives. I can in no way wait until the entire stream is finished, as is often described elsewhere. I have tried using the XmlReader class but its documentation is weird, the methods don't work out, the first element is lost and after sending the second element, an XmlException occurs because there are two root elements.

Try this:
var settings = new XmlReaderSettings
{
ConformanceLevel = ConformanceLevel.Fragment
};
using (var reader = XmlReader.Create(stream, settings))
{
while (!reader.EOF)
{
reader.MoveToContent();
var doc = XDocument.Load(reader.ReadSubtree());
Console.WriteLine("X={0}, Y={1}",
(int)doc.Root.Element("x"),
(int)doc.Root.Element("y"));
reader.ReadEndElement();
}
}

If you change the "conformance level" to "fragment", it might work with the XmlReader.
This is a (slightly modified) example from MSDN:
XmlReaderSettings settings = new XmlReaderSettings();
settings.ConformanceLevel = ConformanceLevel.Fragment;
XmlReader reader = XmlReader.Create(streamOfXmlFragments, settings);

You could use XElement.Load which is meant more for streaming of Xml Element fragments that is new in .net 3.5 and also supports reading directly from a stream.
Have a look at System.Xml.Linq
I think that you may well still have to add some control logic so as to partition the messages you are receiving, but you may as well give it a go.

I'm not sure there's anything built-in that does that.
I'd open a string builder, fill it until I see a </status> tag, and then parse it using the ordinary XmlDocument.

Not substantially different from dtb's solution, but linqier
static IEnumerable<XDocument> GetDocs(Stream xmlStream)
{
var xmlSettings = new XmlReaderSettings() { ConformanceLevel = ConformanceLevel.Fragment };
using (var xmlReader = XmlReader.Create(xmlStream, xmlSettings))
{
var xmlPathNav = new XPathDocument(xmlReader).CreateNavigator();
foreach (var selectee in xmlPathNav.Select("/*").OfType<XPathNavigator>())
yield return XDocument.Load(selectee.ReadSubtree());
}
}
I ran into a similar problem in PowerShell, but the asker's question was in C#, so I've attempted to translate it (and verified that it works). Here is where I found the clue that got me over the last little bumps (". . .The way the XPathDocument does its magic is by creating a “transparent” root node, and holding the fragments from it. I say it’s transparent because your XPath queries can use the root node axis and still get properly resolved to the fragments. . .")
The fragments of XML I'm working with happen to be smallish. If you had bigger chunks, you'd probably want to look into XStreamingElement - it can add a lot of complexity but also greatly decrease memory usage when dealing with large volumes of XML.

Writing to XML resource file through serialization

So I'm writing a C# app that has a couple of XML files added as resources. I read from these XML files to populate objects in the code using XML serialization and it works perfectly. So I can access the files like so (I've left some code out, just have the important bits):
using TestApp.Properties;
XmlSerializer serializer = new XmlSerializer(typeof(MapTiles));
StringReader sr = new StringReader(Resources.Maps);
mapTiles = (MapTiles)serializer.Deserialize(sr);
Now however, I'd like to do the opposite. I'd like to take some data and write it to these XML resource files. However, I seem to be running into trouble with this aspect and was hoping someone could see something I'm messing up or let me know what I need to do? Here's what I'm trying to do:
XmlSerializer serializer = new XmlSerializer(typeof(MapTiles));
TextWriter writer = new StreamWriter(Resources.Maps);
serializer.Serialize(writer, tempGroup);
writer.Close();
When I run this code though, I get an error on the 2nd line that says ArgumentException was unhandled - Empty path name is not legal.
So if anyone has any thoughts I would greatly appreciate some tips. Thanks so much.

The exception is being raised because you are passing Resources.Maps into StreamWriter. StreamWriter is handling this as a string and assuming it is file path for the stream. But the file path is empty so it is throwing an exception.
To fix out the StreamWriter line you could specify a local temporary file instead of Resources.Maps or use StringWriter with the default constructor e.g. new StringWriter().
If you are writing .resx files then ResXResourceWriter is the class you need. It will also handle your stream writing too. See http://msdn.microsoft.com/en-us/library/system.resources.resxresourcewriter.aspx and http://msdn.microsoft.com/en-us/library/ekyft91f.aspx. The second page has examples on how to use the class but breifly you would call something like this:
XmlSerializer serializer = new XmlSerializer(typeof(MapTiles));
using (StringWriter stringWriter = new StringWriter())
{
serializer.Serialize(stringWriter, tempGroup);
using (ResXResourceWriter resourceWriter = new ResXResourceWriter("~/App_GlobalResources/some_file.resx"))
{
resourceWriter.AddResource("Maps", stringWriter.ToString());
}
}
If you want to write out an assembly that has a dynamically created resource in it the you can emit a new assembly. In that case have a look here http://msdn.microsoft.com/en-us/library/8ye65dh0.aspx.

The StreamWriter constructor is throwing the exception because Resources.Maps is an empty string.
Check out the documentation on MSDN:
http://msdn.microsoft.com/en-us/library/fysy0a4b.aspx

Hmm, after trying some other things and doing even more research it appears that the problem is that you cannot write to a resource that is part of the application. Something to do with the resource being written into the assembly and therefore it's not writable. So I'll have to modify my approach and write the output to a different file.
Unless of course anyone does know differently. This is just what I've discovered so far. Thanks to those who had some ideas though, much appreciated.

How to validate XML file in C#2.0

I need help on how to validate Xml file simply?
I googled and found some tutorial said about developer can validate XML file based on an exist XSD schema file.(as below snppet).
For my case, I don't have an Xsd file. What can I do? Must I generate an Xsd file with a tool like XSD.exe?
XmlReaderSettings settings = new XmlReaderSettings();
settings.ValidationType = ValidationType.Schema;
settings.Schemas.Add("", "c:\mySchema.xsd");
settings.ValidationEventHandler += new ValidationEventHandler(OnValidationError);
XmlReader reader = XmlReader.Create("", settings);
XPathDocument doc = new XPathDocument(reader);
XPathNavigator navigatore = doc.CreateNavigator();
Actually the validation what I need is a very simple usage. Just make sure all the xml listed items/inner sub-items are paired. I will open and write my XML, but my XML can't be written successfully for some reason some time. Then when I load my XML next time, my Application will throw exception. That's why I need validate my xml file before load it.
Appreciated for your comments and suggestions.

If you don't have an xsd you should create one. If you are trying to validate any specific structure this is your best option.
If you just want to make sure a document is made up of valid XML you could get away with not having one but if you care about the schema then you must create a schema definition.
You can write your own XSD or use any number of tools. My advice is to write your own. It's not hard and it's worth knowing how to do.
Here is a link to get you started: http://www.w3schools.com/schema/default.asp