Section.HasHeader(HeaderFooterType) Method

Document document = server.Document;
Section firstSection = document.Sections[0];
// Create an empty header.
SubDocument newHeader = firstSection.BeginUpdateHeader();
firstSection.EndUpdateHeader(newHeader);
// Check whether the document already has a header (the same header for all pages).
if (firstSection.HasHeader(HeaderFooterType.Primary))
{
    SubDocument headerDocument = firstSection.BeginUpdateHeader();
    document.ChangeActiveDocument(headerDocument);
    document.CaretPosition = headerDocument.CreatePosition(0);
    firstSection.EndUpdateHeader(headerDocument);
}

Dim document As Document = server.Document
Dim firstSection As Section = document.Sections(0)
' Create an empty header.
Dim newHeader As SubDocument = firstSection.BeginUpdateHeader()
firstSection.EndUpdateHeader(newHeader)
' Check whether the document already has a header (the same header for all pages).
If firstSection.HasHeader(HeaderFooterType.Primary) Then
    Dim headerDocument As SubDocument = firstSection.BeginUpdateHeader()
    document.ChangeActiveDocument(headerDocument)
    document.CaretPosition = headerDocument.CreatePosition(0)
    firstSection.EndUpdateHeader(headerDocument)
End If