Adding Image watermark to Pdf while Creating it using iTextSharp?

Hi Sagar ,

To add an image watermark to a PDF while creating it using iTextSharp with ASP.Net backed with VB.Net, you can follow these steps:

Step 1: Install iTextSharp library Make sure you have the iTextSharp library installed in your project. You can install it via NuGet by right-clicking on your project in Visual Studio and selecting "Manage NuGet Packages." Search for "iTextSharp" and install the appropriate package.

Step 2: Import necessary namespaces In your VB.Net code file, import the necessary namespaces for iTextSharp:

Here is code snipped :

Import necessary namespaces

Imports iTextSharp.text
Imports iTextSharp.text.pdf

Create a PDF document

Dim document As New Document(PageSize.A4, 50, 50, 50, 50)

Create a PdfWriter

Dim writer As PdfWriter = PdfWriter.GetInstance(document, New FileStream("path/to/output.pdf", FileMode.Create))

Add content to the document

document.Open()

Dim imagePath As String = "path/to/image.png"
Dim image As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(imagePath)
document.Add(image)

Dim watermarkImagePath As String = "path/to/watermark.png"
Dim watermarkImage As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(watermarkImagePath)
watermarkImage.SetAbsolutePosition(200, 400) ' Set the position of the watermark image on the page

Dim pageCount As Integer = document.PageNumber
For i As Integer = 1 To pageCount
    document.SetPageSize(PageSize.A4)
    document.NewPage()
    document.Add(watermarkImage)
Next

document.Close()

Check this

Dim document As New Document()
Dim writer As PdfWriter = PdfWriter.GetInstance(document, New FileStream("path/to/output.pdf", FileMode.Create))
document.Open()

' Add content to the document

' Add tables, additional text, etc.
document.Add(New Paragraph("Hello, World!"))

Dim table As New PdfPTable(1)
Dim cell As New PdfPCell(New Phrase("Hello, World!"))
table.AddCell(cell)
document.Add(table)

' Create a watermark object
Dim watermark As PdfContentByte = writer.DirectContentUnder

' Load the watermark image
Dim watermarkImage As Image = Image.GetInstance("path/to/watermark.png")
watermarkImage.SetAbsolutePosition(100, 100)

' Set the transparency of the watermark
watermark.SetGState(New PdfGState() With {.FillOpacity = 0.5F})

' Add the watermark to each page
For i As Integer = 1 To writer.PageNumber
    watermark.AddImage(watermarkImage)
    watermark.BeginText()
    watermark.EndText()
Next
document.Close()