Generating UTF-8 with System.Xml.XmlWriter

Today i decided to experiment with XmlWriter. The first i wanted to do was set the Encoding to UTF-8.:

StringBuilder stringBuilder = new StringBuilder();
XmlWriter xmlWriter = XmlWriter.Create(stringBuilder);
xmlWriter.Settings.Encoding = Encoding.UTF8;

When i ran this code i recieved the following exception: XmlException was unhandled: The "XmlWriterSettings.Encoding" property is read only and cannot be set. The documentation for the Settings property clearly says:

The XmlWriterSettings object returned by the Settings property cannot be modified. Any attempt to change individual settings results in an exception being thrown.

So i wrote the following:

StringBuilder stringBuilder = new StringBuilder();
XmlWriterSettings xmlWriterSettings = new XmlWriterSettings();
xmlWriterSettings.Encoding = Encoding.UTF8;
 
XmlWriter xmlWriter = XmlWriter.Create(stringBuilder, xmlWriterSettings);
xmlWriter.WriteStartDocument();
xmlWriter.WriteStartElement("root", "http://www.timvw.be/ns");
xmlWriter.WriteEndElement();
xmlWriter.WriteEndDocument();
xmlWriter.Flush();
xmlWriter.Close();
 
string xmlString = stringBuilder.ToString();

As you can see: is still not what i want. Apparently is the Encoding property ignored if the XmlWriter is not using a Stream. So here is my next attempt:

MemoryStream memoryStream = new MemoryStream();
// initialize xmlWriterSettings as above...
 
XmlWriter xmlWriter = XmlWriter.Create(memoryStream, xmlWriterSettings);
// call the same operations on the xmlWriter as above...
 
string xmlString = Encoding.UTF8.GetString(memoryStream.ToArray());

Ok, i'm getting close:

?

Luckily enough i knew that the ? (byte with value 239) at the beginning is the BOM (Byte Order Mark). In order to get rid of that byte i had to create my own instance of UTF8Encoding. Finally, i can present some working code:

MemoryStream memoryStream = new MemoryStream();
XmlWriterSettings xmlWriterSettings = new XmlWriterSettings();
xmlWriterSettings.Encoding = new UTF8Encoding(false);
xmlWriterSettings.ConformanceLevel = ConformanceLevel.Document;
xmlWriterSettings.Indent = true;
 
XmlWriter xmlWriter = XmlWriter.Create(memoryStream, xmlWriterSettings);
xmlWriter.WriteStartDocument();
xmlWriter.WriteStartElement("root", "http://www.timvw.be/ns");
xmlWriter.WriteEndElement();
xmlWriter.WriteEndDocument();
xmlWriter.Flush();
xmlWriter.Close();
 
string xmlString = Encoding.UTF8.GetString(memoryStream.ToArray());

Trovato qui.