Here Mudassar Ahmed Khan has explained with an example, how to export GridView to PDF with Header Repeated on each Page using iTextSharp in ASP.Net with C# and VB.Net.
When the Export Button is clicked, a loop will be executed over the GridView Pages using PageCount property and GridView records for specific Page will be added to a new page of PDF.
Thus, using this technique each Page of PDF will have records of one Page of GridView with Header.