添加一个新的页面到PDF文档c#

我需要在使用下面的代码创建的pdf文件中添加另一个页面。下一页也应该使用放置在path:

的相同模板。

HostingEnvironment.MapPath("~/Content/InvoiceTemplate/invoiceTemplate.pdf")

我正在使用itextsharp库来创建文档。下面是用于生成pdf的代码。

public static void WriteInTemplate(List<Models.Statement> statementList)
{
    string invoiceNumber = statementList.FirstOrDefault().Invoice.ToString().Trim();
    string month = null;
    string day = null;
    string year = null;

    PdfReader pdfReader = new PdfReader(HostingEnvironment.MapPath("~/Content/InvoiceTemplate/invoiceTemplate.pdf"));
    FileStream fileStream = new FileStream(HostingEnvironment.MapPath("~/Content/reports/" + invoiceNumber + ".pdf"), FileMode.Create);
    PdfStamper pdfStamper = new PdfStamper(pdfReader, fileStream);

    AcroFields pdfFields = pdfStamper.AcroFields;

    pdfFields.SetField("BillToCompany", statementList.FirstOrDefault().BillToCompany.ToString().Trim().ToUpper());
    pdfFields.SetField("BillToContact", statementList.FirstOrDefault().BillToContact.ToString().Trim().ToUpper());
    pdfFields.SetField("CustomerId", statementList.FirstOrDefault().Customer_ID);
    pdfFields.SetField("InvoiceNumber", statementList.FirstOrDefault().Invoice.ToString().Trim());
    pdfFields.SetField("JobNumber", statementList.FirstOrDefault().JobNumber.ToString().Trim());
    pdfFields.SetField("Caller", statementList.FirstOrDefault().Caller.ToString().Trim());

    pdfStamper.FormFlattening = true; // generate a flat PDF 
    pdfStamper.Close();
    pdfReader.Close();
}