Full page waternark using MVC and iTextSharp

PDF full page watermark using MVC and iTextSharp

Download : Source Code

Most of the time we have requirement to generate pdf with water mark to secure and tried to protect from forgery. Here, I will explain how to implement iTextSharp dll in MVC application to create full page watermark in existing pdf.

Step 1:

First of all create MVC web application and install iTextSharp package through Nuget package manager or nugget command mentioned below.

More detail: https://www.nuget.org/packages/itextsharp.xfaworker.

Step 2:

Open the controller Home from controller folder in MVC application and add the following ActionResult method in the page.

        public ActionResult GetWaterMarkPdf()
        {
            // Source File Path
            string originalFile = Server.MapPath("~/Attachment/Sample.pdf");

            // Destination File path
            string destinationpath = Server.MapPath("~/Attachment/SamplewithWaterMark.pdf");

            // Read file from file location
            PdfReader reader = new PdfReader(originalFile);

            //define font size and style
            Font font = new Font(FontFamily.HELVETICA, 10);

            using (MemoryStream memoryStream = new MemoryStream())
            {
                using (var pdfStamper = new PdfStamper(reader, memoryStream, '\0'))
                {
                    // Getting total number of pages of the Existing Document
                    int pageCount = reader.NumberOfPages;

                    // Create two New Layer for Watermark
                    PdfLayer layer = new PdfLayer("WatermarkLayer", pdfStamper.Writer);
                    PdfLayer layer2 = new PdfLayer("WatermarkLayer2", pdfStamper.Writer);

                    // Loop through each Page

                    string layerwarkmarktxt = "water mark"; // define text for 
                    string Layer2warkmarktxt = "Confidential";
                    for (int i = 1; i <= pageCount; i++)
                    {
                        // Getting the Page Size
                        Rectangle rect = reader.GetPageSize(i);

                        // Get the ContentByte object
                        PdfContentByte cb = pdfStamper.GetUnderContent(i);


                        // Tell the cb that the next commands should be "bound" to this new layer

                        // Start Layer

                        cb.BeginLayer(layer);


                        PdfGState gState = new PdfGState();

                        gState.FillOpacity = 0.1f; // define opacity level
                        cb.SetGState(gState);

                        // set font size and style for layer water mark text
                        cb.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED), 10);

                        List<string> watermarkList = new List<string>();
                        float singleWaterMarkWidth = cb.GetEffectiveStringWidth(layerwarkmarktxt, false);

                        float fontHeight = 10;

                        //Work out the Watermark for a Single Line on the Page based on the Page Width
                        float currentWaterMarkWidth = 0;
                        while (currentWaterMarkWidth + singleWaterMarkWidth < rect.Width)
                        {
                            watermarkList.Add(layerwarkmarktxt);
                            currentWaterMarkWidth = cb.GetEffectiveStringWidth(string.Join(" ", watermarkList), false);
                        }

                        //Fill the Page with Lines of Watermarks
                        float currentYPos = rect.Height;

                        //cb.BeginText();
                        while (currentYPos > 0)
                        {
                            ColumnText.ShowTextAligned(cb, Element.ALIGN_CENTER, new Phrase(string.Join(" ", watermarkList), font), rect.Width / 2, currentYPos, 0, PdfWriter.RUN_DIRECTION_RTL, 1);
                           
                            currentYPos -= fontHeight;
                        }


                        cb.EndLayer();

                        // End First Layer

                        //**************************************************************//

                        // Start Layer 2

                        // Tell the cb that the next commands should be "bound" to this new layer
                        cb.BeginLayer(layer2);
                        Font f = new Font(FontFamily.HELVETICA, 50);                        

                        gState = new PdfGState();
                        gState.FillOpacity = 0.1f;
                        cb.SetGState(gState);

                        cb.SetColorFill(BaseColor.BLACK);

                        //cb.BeginText();
                        ColumnText.ShowTextAligned(cb, Element.ALIGN_CENTER, new Phrase(string.Join(" ", Layer2warkmarktxt), f), rect.Width / 2, rect.Height / 2, 45f, PdfWriter.RUN_DIRECTION_RTL, 1);
                        
                        // Close the layer
                        cb.EndLayer();

                        // End Layer 2
                    }




                }

               // Save file to destination location if required
                if (System.IO.File.Exists(destinationpath))
                {
                    System.IO.File.Delete(destinationpath);
                }
                System.IO.File.WriteAllBytes(destinationpath, memoryStream.ToArray());
            }

            // send file to browse to open it from destination location.
            return File(destinationpath, "application/pdf");
        }

Now after paste this code we need to call GetWaterMarkPdf() method from view

Open the Index View in Home folder delete all the html text and add one action link like shown as below.

@Html.ActionLink("Download water mark pdf", "GetWaterMarkPdf", "Home",  null,  new { target = "_blank" })

After adding action link in the view run the web applicaiton and you will see the page looks like below.

Press the download water mark pdf button and then browser will open the watermark pdf file as shown below.

You can see in the background watermark text emboss below the text and image as well as "confidential" written in the middle of the page at 45 degree angle.

Download : Source Code