private void Form1_Load(object sender, EventArgs e)
{
string workingFolder = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
string startFile = Path.Combine(workingFolder, "StartFile.pdf");
string watermarkedFile = Path.Combine(workingFolder, "Watermarked.pdf");
string unwatermarkedFile = Path.Combine(workingFolder, "Un-watermarked.pdf");
string watermarkText = "This is a test";
//SECTION 1
//Create a 5 page PDF, nothing special here
using (FileStream fs = new FileStream(startFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (Document doc = new Document(PageSize.LETTER)) {
using (PdfWriter witier = PdfWriter.GetInstance(doc, fs)) {
doc.Open();
for (int i = 1; i <= 5; i++)
{
doc.NewPage();
doc.Add(new Paragraph(String.Format("This is page {0}", i)));
}
doc.Close();
}
}
}
//SECTION 2
//Create our watermark on a separate layer. The only different here is that we are adding the watermark to a PdfLayer which is an OCG or Optional Content Group
PdfReader reader1 = new PdfReader(startFile);
using (FileStream fs = new FileStream(watermarkedFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (PdfStamper stamper = new PdfStamper(reader1, fs)) {
int pageCount1 = reader1.NumberOfPages;
//Create a new layer
PdfLayer layer = new PdfLayer("WatermarkLayer", stamper.Writer);
for (int i = 1; i <= pageCount1; i++)
{
iTextSharp.text.Rectangle rect = reader1.GetPageSize(i);
//Get the ContentByte object
PdfContentByte cb = stamper.GetUnderContent(i);
//Tell the CB that the next commands should be "bound" to this new layer
cb.BeginLayer(layer);
cb.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED), 50);
PdfGState gState = new PdfGState();
gState.FillOpacity = 0.25f;
cb.SetGState(gState);
cb.SetColorFill(BaseColor.BLACK);
cb.BeginText();
cb.ShowTextAligned(PdfContentByte.ALIGN_CENTER, watermarkText, rect.Width / 2, rect.Height / 2, 45f);
cb.EndText();
//"Close" the layer
cb.EndLayer();
}
}
}
//SECTION 3
//Remove the layer created above
//First we bind a reader to the watermarked file, then strip out a bunch of things, and finally use a simple stamper to write out the edited reader
PdfReader reader2 = new PdfReader(watermarkedFile);
//NOTE, This will destroy all layers in the document, only use if you don't have additional layers
//Remove the OCG group completely from the document.
//reader2.Catalog.Remove(PdfName.OCPROPERTIES);
//Clean up the reader, optional
reader2.RemoveUnusedObjects();
//Placeholder variables
PRStream stream;
String content;
PdfDictionary page;
PdfArray contentarray;
//Get the page count
int pageCount2 = reader2.NumberOfPages;
//Loop through each page
for (int i = 1; i <= pageCount2; i++)
{
//Get the page
page = reader2.GetPageN(i);
//Get the raw content
contentarray = page.GetAsArray(PdfName.CONTENTS);
if (contentarray != null)
{
//Loop through content
for (int j = 0; j < contentarray.Size; j++)
{
//Get the raw byte stream
stream = (PRStream)contentarray.GetAsStream(j);
//Convert to a string. NOTE, you might need a different encoding here
content = System.Text.Encoding.ASCII.GetString(PdfReader.GetStreamBytes(stream));
//Look for the OCG token in the stream as well as our watermarked text
if (content.IndexOf("/OC") >= 0 && content.IndexOf(watermarkText) >= 0)
{
//Remove it by giving it zero length and zero data
stream.Put(PdfName.LENGTH, new PdfNumber(0));
stream.SetData(new byte[0]);
}
}
}
}
//Write the content out
using (FileStream fs = new FileStream(unwatermarkedFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (PdfStamper stamper = new PdfStamper(reader2, fs)) {
}
}
this.Close();
}
public Example5()
{
string appRootDir = new DirectoryInfo(Environment.CurrentDirectory).Parent.Parent.FullName;
string startFile = appRootDir + "/PDFs/" + "Chapter1_Example5.pdf";
string watermarkedFile = appRootDir + "/PDFs/" + "Chapter1_Example5_Watermarked.pdf";
string unwatermarkedFile = appRootDir + "/PDFs/" + "Chapter1_Example5_Un-Watermarked.pdf";
string watermarkText = "This is a Test";
// Creating a Five paged PDF
using (FileStream fs = new FileStream(startFile, FileMode.Create, FileAccess.Write, FileShare.None))
using (Document doc = new Document(PageSize.LETTER))
using (PdfWriter writer = PdfWriter.GetInstance(doc, fs))
{
doc.Open();
for (int i = 1; i <= 5; i++)
{
doc.NewPage();
doc.Add(new Paragraph(string.Format("This is a page {0}", i)));
}
doc.Close();
}
// Creating watermark on a separate layer
// Creating iTextSharp.text.pdf.PdfReader object to read the Existing PDF Document produced by 1 no.
PdfReader reader1 = new PdfReader(startFile);
using (FileStream fs = new FileStream(watermarkedFile, FileMode.Create, FileAccess.Write, FileShare.None))
// Creating iTextSharp.text.pdf.PdfStamper object to write Data from iTextSharp.text.pdf.PdfReader object to FileStream object
using (PdfStamper stamper = new PdfStamper(reader1, fs))
{
// Getting total number of pages of the Existing Document
int pageCount = reader1.NumberOfPages;
// Create New Layer for Watermark
PdfLayer layer = new PdfLayer("WatermarkLayer", stamper.Writer);
// Loop through each Page
for (int i = 1; i <= pageCount; i++)
{
// Getting the Page Size
Rectangle rect = reader1.GetPageSize(i);
// Get the ContentByte object
PdfContentByte cb = stamper.GetUnderContent(i);
// Tell the cb that the next commands should be "bound" to this new layer
cb.BeginLayer(layer);
cb.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED), 50);
PdfGState gState = new PdfGState();
gState.FillOpacity = 0.25f;
cb.SetGState(gState);
cb.SetColorFill(BaseColor.BLACK);
cb.BeginText();
cb.ShowTextAligned(PdfContentByte.ALIGN_CENTER, watermarkText, rect.Width / 2, rect.Height / 2, 45f);
cb.EndText();
// Close the layer
cb.EndLayer();
}
}
// Removing the layer created above
// 1. First we bind a reader to the watermarked file
// 2. Then strip out a branch of things
// 3. Finally use a simple stamper to write out the edited reader
PdfReader reader2 = new PdfReader(watermarkedFile);
// NOTE: This will destroy all layers in the Document, only use if you don't have any addtional layers
// Remove the OCG group completely from the Document: reader2.Catalog.Remove(PdfName.OCPROPERTIES);
// Clean up the reader, optional
reader2.RemoveUnusedObjects();
// Placeholder variables
PRStream stream;
string content;
PdfDictionary page;
PdfArray contentArray;
// Get the number of pages
int pageCount2 = reader2.NumberOfPages;
// Loop through each page
for (int i = 1; i <= pageCount2; i++)
{
// Get the page
page = reader2.GetPageN(i);
// Get the raw content
contentArray = page.GetAsArray(PdfName.CONTENTS);
if (contentArray != null)
{
// Loop through content
for (int j = 0; j < contentArray.Size; j++)
{
stream = (PRStream)contentArray.GetAsStream(j);
// Convert to a String, NOTE: you might need a different encoding here
content = System.Text.Encoding.ASCII.GetString(PdfReader.GetStreamBytes(stream));
//Look for the OCG token in the stream as well as our watermarked text
if (content.IndexOf("/OC") >= 0 && content.IndexOf(watermarkText) >= 0)
{
//Remove it by giving it zero length and zero data
stream.Put(PdfName.LENGTH, new PdfNumber(0));
stream.SetData(new byte[0]);
}
}
}
}
// Write the content out
using (FileStream fs = new FileStream(unwatermarkedFile, FileMode.Create, FileAccess.Write, FileShare.None))
using (PdfStamper stamper = new PdfStamper(reader2, fs)) { }
}
