I am getting multiple headers and footers in word document, getting null in policy.GetFirstPageHeader() using NPOI - ms-word

Question

I am getting multiple headers and footers in a Word document; I cannot differentiate the firstpage, default(odd), or even headers.
When I am trying to call policy.GetFirstPageHeader() I am getting a null value.
XWPFHeaderFooterPolicy policy = new XWPFHeaderFooterPolicy(document);
var headerList = document.HeaderList;
var footerList = document.FooterList;
var firstPageHeader = policy.GetFirstPageHeader();
var firstPageFooter = policy.GetFirstPageFooter();
XWPFHeader header = policy.GetDefaultHeader();
XWPFHeader even = policy.GetEvenPageHeader();
XWPFHeader odd = policy.GetOddPageHeader();
I am getting null values. Can any one suggest how to differentiate headers in a Word document?

Answer 1

var listOfheaders = new List<CT_HdrFtrRef>();
foreach (var par in document.Paragraphs)
{
var ParagraphsectPr = (CT_P)par.GetType().GetField("paragraph", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(par);
if (ParagraphsectPr.pPr.sectPr != null)
{
foreach (var headerref in ParagraphsectPr.pPr.sectPr.headerReference)
{
listOfheaders.Add(headerref);
}
}
}
foreach (var list in listOfheaders)
{
var relatedPart = document.GetRelationById(list.id);
XWPFHeader hdr = null;
if (relatedPart != null && relatedPart is XWPFHeader)
{
hdr = (XWPFHeader)relatedPart;
}
// Assign it
ST_HdrFtr type = list.type;
if (!string.IsNullOrEmpty(hdr.Text))
{
if (type == ST_HdrFtr.first)
{
firstPageHeadr = hdr;
}
else if (type == ST_HdrFtr.even)
{
evenPageHeader = hdr;
}
else
{
defaultHeader = hdr;
}
}
}