How to force XDocument to output the prolog in uppercase while preserving identation and formatting?

Question

I want XDocument to output the XML prolog (for example \"\") in uppercase.

Here is how I\'m cur

Answer 1

I had the same problem, the program that should read the XML could not handle the "utf" in lower case.

Found this simple workaround:

    XmlWriterSettings settings = new XmlWriterSettings();

    settings.Indent = true;
    settings.OmitXmlDeclaration = true;
    settings.NewLineHandling = NewLineHandling.Replace;
    settings.NewLineOnAttributes = true;       

                using (
                    XmlWriter xmlWriter =
                        XmlWriter.Create(
                            Application.StartupPath + @"\Output\products.xml", settings))
                {

                    xmlWriter.WriteStartDocument();
                    xmlWriter.WriteRaw("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n");
                    xmlWriter.WriteStartElement("products");

etc....

Answer 2

Here is a sample solution using XmlTextWriter

I am sure there should be a better optimal way..

            XDocument doc = new XDocument(new XDeclaration("1.0", "UTF-8","d"));
            doc.Add(new XElement("MyRoot", "Value blah"));


            using (var str = new StringWriter())
            using (var xmlTextWriter = new XmlTextWriter(str))
            {
                xmlTextWriter.Formatting = Formatting.Indented;
                xmlTextWriter.Indentation = 4;

                xmlTextWriter.WriteRaw(doc.Declaration.ToString().ToUpper());

                foreach (var xElement in doc.Elements())
                {
                   xmlTextWriter.WriteElementString(xElement.Name.ToString(), xElement.Value);
                }

                var finalOutput = str.ToString();
            }

FinalOutput would contain:

<?XML VERSION="1.0" ENCODING="UTF-8" STANDALONE="D"?>
<MyRoot>Value blah</MyRoot>

Answer 3

XDocument xdoc = new XDocument();

.... // do your stuff here

string finalDoc = xdoc.ToString();
string header = finalDoc.Substring(0,finalDoc.IndexOf("?>") + 2); // end of header tag

finalDoc = finalDoc.Replace(header, header.ToUpper());  // replace header with the uppercase version

.... // do stuff with the xml with the upper case header

EDIT:

Oh you only want the UTF-8 upper case?

Then this is more correct:

XDocument xdoc = new XDocument();

.... // do your stuff here

string finalDoc = xdoc.ToString();
string header = finalDoc.Substring(0,finalDoc.IndexOf("?>") + 2); // end of header tag
string encoding = header.Substring(header.IndexOf("encoding=") + 10);
encoding = encoding.Substring(0,encoding.IndexOf("\""); // only get encoding content

// replace encoding with the uppercase version in header, then replace old header with new one.
finalDoc = finalDoc.Replace(header, header.Replace(encoding, encoding.ToUpper()));

.... // do stuff with the xml with the upper case header

This will only replace whatever is in the encoding to uppercase manually.

Answer 4

Save to a custom stream that modify the header and then pass it on to a FileStream.