Generating OpenXML DocProperties Id

Question

I need to add something to a word document via OpenXML. I've used the Open Xml productivity tool to generate the code and I'm trying to tweak it so it's reusable for all documents.

Apparently a DocProperties object is required, which requires a unique Id. Is there a way to generate these Id's automatically? Or do I need to do something like the code below to find the max Id used and increment from there?

Is there a better way? This seems expensive. I'm using DocumentFormat.OpenXml from the Open XML SDK (v2.5) from Microsoft in C# with .Net 4.0.

static uint getMaxDocPropertyId(WordprocessingDocument doc)
{
  return doc
      .MainDocumentPart
      .Parts
      .Select(x => x.OpenXmlPart.RootElement)
      .Where(x => x != null)
      .SelectMany(x => x.Descendants<Wp.DocProperties>())
      .Max(x => x.Id.Value as uint?) ?? 0;
}

Answer 1

This worked for me, but it is essentially doing the same thing. For me, I don't think it can be avoided since the DocProperties I'm looking for belong to images and I have more than one in my document so each one is buried deep inside of a paragraph -> Run -> Drawing -> and a child of Inline.

private uint GetMaxDocPropertyId(WordprocessingDocument doc)
{
    return doc
       .MainDocumentPart
       .RootElement
       .Descendants<DocProperties>()
       .Max(x => (uint?) x.Id ) ?? 0;
}