Image文件生成PDF(多页)

Image文件生成PDF文件，可多页，可设置纸张大小

/// <summary>
        /// Image文件生成PDF
        /// </summary>
        /// <param name="pdfPath">PDF存放路径</param>
        /// <param name="imgs">source</param>
        /// <returns></returns>
        private static void CreatePDFFiles(string pdfPath, List<System.Drawing.Image> imgs)
        {
            try
            {
                var document = new Document(iTextSharp.text.PageSize.A4, 25, 25, 25, 25);
                using (var stream = new FileStream(pdfPath, FileMode.Create, FileAccess.Write, FileShare.None))
                {
                    PdfWriter.GetInstance(document, stream);
                    document.Open();

                    try
                    {
                        foreach (System.Drawing.Image img in imgs)
                        {
                            iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(img, BaseColor.WHITE);

                            if (image.Height > iTextSharp.text.PageSize.A4.Height - 25)
                            {
                                image.ScaleToFit(iTextSharp.text.PageSize.A4.Width - 25, iTextSharp.text.PageSize.A4.Height - 25);
                            }
                            else if (image.Width > iTextSharp.text.PageSize.A4.Width - 25)
                            {
                                image.ScaleToFit(iTextSharp.text.PageSize.A4.Width - 25, iTextSharp.text.PageSize.A4.Height - 25);
                            }
                            image.Alignment = iTextSharp.text.Image.ALIGN_MIDDLE;
                            document.Add(image);
                            document.NewPage();
                        }
                    }
                    catch (Exception ex)
                    {
                    }

                    document.Close();
                    stream.Close();
                }

            }
            catch (Exception ex)
            {
                //ret = ex.ToString();
            }

        }