In C#, what is the best method to format a string as XML?

Question

I am creating a lightweight editor in C# and would like to know the best method for converting a string into a nicely formatted XML string. I would hope that there's a public method in the C# library like "public bool FormatAsXml(string text, out string formattedXmlText)", but it couldn't be that easy, could it?

Very specifically, what would the method "SomeMethod" have to be that would produce the output below?

string unformattedXml;
string formattedXml;

unformattedXml = "<?xml version="1.0"?><book><author>Lewis, C.S.</author><title>The Four Loves</title></book>"
formattedXml = SomeMethod(unformattedXml);

Console.WriteLine(formattedXml);

Output:

<?xml version="1.0"?>
  <book id="123">
    <author>Lewis, C.S.</author>
    <title>The Four Loves</title>
  </book>

question from:https://stackoverflow.com/questions/194944/in-c-what-is-the-best-method-to-format-a-string-as-xml

Answer 1

string unformattedXml = "<?xml version="1.0"?><book><author>Lewis, C.S.</author><title>The Four Loves</title></book>";
string formattedXml = XElement.Parse(unformattedXml).ToString();
Console.WriteLine(formattedXml);

Output:

<book>
  <author>Lewis, C.S.</author>
  <title>The Four Loves</title>
</book>

The Xml Declaration isn't output by ToString(), but it is by Save() ...

  XElement.Parse(unformattedXml).Save(@"C:doc.xml");
  Console.WriteLine(File.ReadAllText(@"C:doc.xml"));

Output:

<?xml version="1.0" encoding="utf-8"?>
<book>
  <author>Lewis, C.S.</author>
  <title>The Four Loves</title>
</book>