Unable to encode to UTF8 with XmlWriter

Question

I'm working on a web service in WCF.

I want to return a xml file, in UTF8.

My code is :

StringBuilder output = new StringBuilder();
XmlWriterSettings settings = new XmlWriterSettings { Indent = true, Encoding = Encoding.UTF8 };
using (XmlWriter writer = XmlWriter.Create(output, settings))
{
    writer.WriteStartDocument();
    writer.WriteStartElement("Response", Resources.nameSpaceUri);
    /* Some functions */
    writer.WriteEndElement();
    writer.WriteEndDocument();
}
return output.ToString();

But the result is something like :

<?xml version="1.0" encoding="utf-16"?>
<Response xmlns="http://namespace">
    <!-- Content -->
</Response>

Why my response is in UTF-16 ?

Answer 1

It's simply because StringBuilder (and String, Char, char) use UTF-16. The writer declares the encoding appropriately. If you use a writer that targets a file or stream then it uses the encoding from the settings.