public PDFHelper(float width, float height)
{
m_width = width;
m_height = height;
m_doc = new iTextSharp.text.Document(new iTextSharp.text.Rectangle(0, 0, Width, Height));
m_stream = new System.IO.MemoryStream();
m_writer = iTextSharp.text.pdf.PdfWriter.GetInstance(m_doc, m_stream);
m_doc.OpenDocument();
m_canvas = Writer.DirectContent;
Canvas.SetColorStroke(BaseColor.BLACK);
Canvas.SetColorFill(BaseColor.WHITE);
}