[VB.Net] Add watermark to existing Pdf file using iTextSharp

[gnoter]

For those of us who find this solution via a web search and want a C# (C-Sharp) version, here it is, tested and working.

Foremost: Major thx to stanav; excellent post.

You'll note there are 2 functions, with the first functions calling the second function. This mimics the "OPTIONAL" params in VB

public static void AddWatermarkTextC(string sourceFile, string outputFile, string[] watermarkText)
  {
    iTextSharp.text.pdf.BaseFont tWatermarkFont = null;
    float tWatermarkFontSize = 48F;
    iTextSharp.text.Color tWatermarkFontColor = null;
    float tWatermarkFontOpacity = 0.3F;
    float tWatermarkRotation = 45.0F;
 
    tWatermarkFont = iTextSharp.text.pdf.BaseFont.CreateFont(iTextSharp.text.pdf.BaseFont.HELVETICA, iTextSharp.text.pdf.BaseFont.CP1252, iTextSharp.text.pdf.BaseFont.NOT_EMBEDDED);
    tWatermarkFontColor = iTextSharp.text.Color.BLUE;
    AddWatermarkTextC(sourceFile, outputFile, watermarkText, tWatermarkFont, tWatermarkFontSize, tWatermarkFontColor, tWatermarkFontOpacity, tWatermarkRotation);
  }//void AddWatermarkTextC(string sourceFile, string outputFile, string[] watermarkText )
 
 
  public static void AddWatermarkTextC(string sourceFile, string outputFile, string[] watermarkText, iTextSharp.text.pdf.BaseFont watermarkFont, float watermarkFontSize, iTextSharp.text.Color watermarkFontColor, float watermarkFontOpacity, float watermarkRotation)
  {
 
    iTextSharp.text.pdf.PdfReader reader = null;
    iTextSharp.text.pdf.PdfStamper stamper = null;
    iTextSharp.text.pdf.PdfGState gstate = null;
    iTextSharp.text.pdf.PdfContentByte underContent = null;
    iTextSharp.text.Rectangle rect = null;
    float currentY = 0.0F;
    float offset = 0.0F;
    int pageCount = 0;
 
    try
    {
      reader = new iTextSharp.text.pdf.PdfReader(sourceFile);
      rect = reader.GetPageSizeWithRotation(1);
      stamper = new iTextSharp.text.pdf.PdfStamper(reader, new System.IO.FileStream(outputFile, System.IO.FileMode.Create));
      if (watermarkFont == null)
      {
        watermarkFont = iTextSharp.text.pdf.BaseFont.CreateFont(iTextSharp.text.pdf.BaseFont.HELVETICA, iTextSharp.text.pdf.BaseFont.CP1252, iTextSharp.text.pdf.BaseFont.NOT_EMBEDDED);
      }//if (watermarkFont == null)
 
      if (watermarkFontColor == null)
      {
        watermarkFontColor = iTextSharp.text.Color.BLUE;
      }//if (watermarkFontColor == null)
 
      gstate = new iTextSharp.text.pdf.PdfGState();
      gstate.FillOpacity = watermarkFontOpacity;
      gstate.StrokeOpacity = watermarkFontOpacity;
      pageCount = reader.NumberOfPages;
      for (int i = 1; i <= pageCount; i++)
      {
        underContent = stamper.GetOverContent(i);
        underContent.SaveState();
        underContent.SetGState(gstate);
        underContent.SetColorFill(watermarkFontColor);
        underContent.BeginText();
        underContent.SetFontAndSize(watermarkFont, watermarkFontSize);
        underContent.SetTextMatrix(30, 30);
        if (watermarkText.Length > 1)
        {
          currentY = (rect.Height / 2) + ((watermarkFontSize * watermarkText.Length) / 2);
        }//if (watermarkText.Length > 1)
        else
        {
          currentY = (rect.Height / 2);
        }//else if (watermarkText.Length > 1)
 
        for (int j = 0; j < watermarkText.Length; j++)
        {
          if (j > 0)
          {
            offset = (j * watermarkFontSize) + (watermarkFontSize / 4) * j;
          }//if (j > 0)
          else
          {
            offset = 0.0F;
          }//else if (j > 0)
 
          underContent.ShowTextAligned(iTextSharp.text.Element.ALIGN_CENTER, watermarkText[j], rect.Width / 2, currentY - offset, watermarkRotation);
        }//for (int j = 0; j < watermarkText.Length; j++)
 
        underContent.EndText();
        underContent.RestoreState();
      }//for (int i = 1; i <= pageCount; i++)
 
      stamper.Close();
      reader.Close();
    }
    catch (Exception ex)
    {
      throw ex;
    }
  }//void AddWatermarkTextC(string sourceFile, string outputFile, string[] watermarkText, iTextSharp.text.pdf.BaseFont watermarkFont, float watermarkFontSize, iTextSharp.text.Color watermarkFontColor, float watermarkFontOpacity, float watermarkRotation)

Signed,

MacSpudster / GNoter
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