Watermark pdf in C#

Watermark created pdf in C#

Steps for creating Pdf watermarked.

• creating new project window application
• download itextsharp from Here
• add reference of itextSharp.dll to your project
• Add a button to form

Add the following functions 

using iTextSharp.text;
using iTextSharp.text.pdf;
using System.IO;

 public Paragraph AddParagragh(string ParagraphText)
        {
            Paragraph p = new Paragraph();
            p.SpacingBefore = 10f;
            p.FirstLineIndent = 10f;
            p.SpacingAfter = 15f;

            iTextSharp.text.Font f = new iTextSharp.text.Font();
            p.Font.SetFamily("Courier");
            p.Alignment = Element.ALIGN_JUSTIFIED;
            p.Font.Size = 13f;
            p.Font.SetColor(0, 0, 0);
            p.Add(ParagraphText);
            return p;
        }
        public Chunk AddParagraphHeader(string headingText)
        {
            Chunk ch = new Chunk(headingText);
            ch.Font.Size = 16f;
            ch.Font.SetStyle("bold");
            ch.Font.SetColor(0, 0, 0);
            return ch;
        }

Add the following code to your button click event

using iTextSharp.text;
using iTextSharp.text.pdf;
using System.IO;

 private void button2_Click(object sender, EventArgs e)
        {
            Document doc = new Document(PageSize.A4);

            try
            {

                PdfWriter writer = PdfWriter.GetInstance(doc, new FileStream(
                  Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "/WaterMark.pdf", FileMode.Create));
                doc.Open();
                doc.Add(this.AddParagraphHeader("Getting ready"));
                doc.Add(this.AddParagragh(@"At the top level, there is a Figure instance containing all that we see and some more (that we don't see). The figure contains, among other things, instances of the Axes class as a Figure.axes field. The Axes instances contain almost everything we care about: all the lines, points, ticks, and labels. So, when we call plot(), we are adding a line (matplotlib.lines.Line2D) to the Axes.lines list. If we plot a histogram (hist()), we are adding rectangles to the list of Axes.patches ('patches' is the term inherited from MATLAB®, and it represents the 'patch of color' concept)."));
                doc.Add(this.AddParagragh(@"An instance of Axes also holds references to the XAxis and YAxis instances, which in turn refer to the x axis and y axis, respectively. The XAxis and YAxis instances manage the drawing of the axis, labels, ticks, tick labels, locators, and formatters. We can reference these through Axes.xaxis and Axes.yaxis, respectively. We don't have to go all the way down to XAxis or YAxis instances to get to the labels as matplotlib gives us a helper method (practically a shortcut) that enables iterations via these labels: matplotlib.pyplot.xlabel() and matplotlib.pyplot.ylabel()."));

                //water mark
                BaseFont bfTimes = BaseFont.CreateFont(BaseFont.TIMES_ITALIC, BaseFont.CP1252, false);
                BaseColor bc = new BaseColor(0, 0, 0, 65);
                iTextSharp.text.Font times = new iTextSharp.text.Font(bfTimes, 145.5F, iTextSharp.text.Font.ITALIC, bc);

                // Dim wfont = New Font(BaseFont.TIMES_ROMAN, 1.0F, BaseFont.COURIER, BaseColor.LIGHT_GRAY)
                ColumnText.ShowTextAligned(writer.DirectContent, Element.ALIGN_CENTER, new Phrase("Confidential", times), 245.5F, 480.0F, -55);

                //End water mark

                doc.Close();
                System.Diagnostics.Process.Start(Environment.GetFolderPath(
                         Environment.SpecialFolder.Desktop) + "/WaterMark.pdf");
            }
            catch (Exception ae)
            {
                doc.Close();
            }
        }

Here is the result