IText&Html2canvas js截圖 繪制 導出PDF

Html2canvas JS截圖

HTML

<div  id="divPDF"> 
需要截圖的區域
</div>

JS

<script src="../Js/html2canvas.js"></script>
<script type="text/javascript">

        function getPDF() {
             html2canvas($('#divPDF'),
             {
                 onrendered: function (canvas) {
                     var imgUrl = canvas.toDataURL();//獲取截圖的Base64編碼
                 }
             });
         }

</script>

 后台使用圖片 Base64編碼轉換為圖像

        // <summary>
        /// Base64編碼轉換為圖像
        /// </summary>
        /// <param name="base64String">Base64字符串</param>
        /// <returns>轉換成功返回圖像；失敗返回null</returns>
        public string Base64ToImage(string imgName, string base64String, string path)
        {
            base64String = base64String.Replace("data:image/png;base64,", "");
            MemoryStream ms = null;
            System.Drawing.Image image = null;
            string imgUrl = path + "\\" + imgName + ".png";
            byte[] imageBytes = Convert.FromBase64String(base64String);
            ms = new MemoryStream(imageBytes, 0, imageBytes.Length);
            ms.Write(imageBytes, 0, imageBytes.Length);
            image = System.Drawing.Image.FromStream(ms, true);
            image.Save(imgUrl);
            return imgUrl;
        }

給PDF文件添加水印 IText  WaterMark

        public void AddWaterMark(string fileLocation, string path, int x, int y)
        {
            string WatermarkLocation = path + "\\watermark.png";
            Document document = new Document();
            PdfReader pdfReader = new PdfReader(fileLocation);
            PdfStamper stamp = new PdfStamper(pdfReader, new FileStream(fileLocation.Replace(".pdf", "[temp][file].pdf"), FileMode.Create));

            iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(WatermarkLocation);
            img.SetAbsolutePosition(x, y); // set the position in the document where you want the watermark to appear (0,0 = bottom left corner of the page)
            PdfContentByte waterMark;
            for (int page = 1; page <= pdfReader.NumberOfPages; page++)
            {  
                waterMark = stamp.GetOverContent(page);
                waterMark.AddImage(img);
            }
            stamp.FormFlattening = true;
            stamp.Close();
            pdfReader.Close();
            // now delete the original file and rename the temp file to the original file
            File.Delete(fileLocation);
            File.Move(fileLocation.Replace(".pdf", "[temp][file].pdf"), fileLocation);

        }