Open XML - How to add a watermark to a docx document

Question

I\'m trying to take an existing document and if a header doesn\'t exist, create one, and then add a watermark to the header that says \"DRAFT\" diagonally. I\'ve followed a

Answer 1

remove the line

doc.MainDocumentPart.DeleteParts(doc.MainDocumentPart.HeaderParts);

AND replace the check for sectionproperties with something similar to

if (doc.MainDocumentPart.Document.Body.Elements().Count == 0)

EDIT:

the complete if then.. would look like this:

var sectionProps = null;

if (doc.MainDocumentPart.Document.Body.Elements().Count == 0)
{
sectionProps = new SectionProperties();
doc.MainDocumentPart.Document.Body.Append(sectionProps);
}
else
{
sectionProps = doc.MainDocumentPart.Document.Body.Elements().Last();
}