iTextSharp.text.Document.SetPageSize C# (CSharp) Method

        public virtual bool SetPageSize(Rectangle pageSize)
        {
            this.pageSize = pageSize;
            foreach (IDocListener listener in listeners) {
                listener.SetPageSize(pageSize);
            }
            return true;
        }

        private static byte[] CreateImagePdf()
        {
            MemoryStream byteStream = new MemoryStream();


            Document document = new Document();
            PdfWriter writer = PdfWriter.GetInstance(document, byteStream);
            document.SetPageSize(PageSize.LETTER);

            document.Open();


            Bitmap awtImg = new Bitmap(100, 100, PixelFormat.Format32bppRgb);
            Graphics g = Graphics.FromImage(awtImg);
            g.FillRectangle(new SolidBrush(Color.Green), 10, 10, 80, 80);
            g.Save();
            Image itextImg = Image.GetInstance(awtImg, (BaseColor)null);
            document.Add(itextImg);

            document.Close();

            byte[] pdfBytes = byteStream.ToArray();

            return pdfBytes;
        }