I am having a source file of pdf.I want to replace specified texts with the code in my c#.I am here using ItextSharp libary and below is my code:

 //using iTextSharp.text.pdf;
 string OrigFile = "Original.pdf";
 string ResultFile = "MyPDF.pdf";
        
 using (PdfReader reader = new PdfReader(OrigFile))
 {
 for (int i = 1; i <= reader.NumberOfPages; i++)
 {
 byte[] contentBytes = reader.GetPageContent(i);
 string contentString = PdfEncodings.ConvertToString(contentBytes, "PDF");                    
 contentString = contentString.Replace(OriginalText, ReplacedText);
 reader.SetPageContent(i,PdfEncodings.ConvertToBytes(contentString,                             PdfObject.TEXT_PDFDOCENCODING));
 }
 new PdfStamper(reader, new FileStream(ResultFile, FileMode.Create,                             FileAccess.Write)).Close();
}

This code doesn’t work and my Result file is not changed with replaced text.
What is the exact problem with the above??Can anyone suggest me.

I have tried this using ItextSharp.