标题概括了所有内容。
我想使用iTextSharp将文本添加到现有的PDF文件中，但是我找不到如何在网络中的任何地方执行此操作...
PS：我不能使用PDF表格。
Answers:
我找到了一种方法（不知道它是否是最好的，但它能奏效）
string oldFile = "oldFile.pdf";
string newFile = "newFile.pdf";
// open the reader
PdfReader reader = new PdfReader(oldFile);
Rectangle size = reader.GetPageSizeWithRotation(1);
Document document = new Document(size);
// open the writer
FileStream fs = new FileStream(newFile, FileMode.Create, FileAccess.Write);
PdfWriter writer = PdfWriter.GetInstance(document, fs);
document.Open();
// the pdf content
PdfContentByte cb = writer.DirectContent;
// select the font properties
BaseFont bf = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252,BaseFont.NOT_EMBEDDED);
cb.SetColorFill(BaseColor.DARK_GRAY);
cb.SetFontAndSize(bf, 8);
// write the text in the pdf content
cb.BeginText();
string text = "Some random blablablabla...";
// put the alignment and coordinates here
cb.ShowTextAligned(1, text, 520, 640, 0);
cb.EndText();
cb.BeginText();
text = "Other random blabla...";
// put the alignment and coordinates here
cb.ShowTextAligned(2, text, 100, 200, 0);
cb.EndText();
// create the new page and add it to the pdf
PdfImportedPage page = writer.GetImportedPage(reader, 1);
cb.AddTemplate(page, 0, 0);
// close the streams and voilá the file should be changed :)
document.Close();
fs.Close();
writer.Close();
reader.Close();
我希望这对某人有用=）（并在此处发布任何错误）
除了上述出色的答案之外，以下内容还显示了如何向多页文档的每一页添加文本：
using (var reader = new PdfReader(@"C:\Input.pdf"))
{
using (var fileStream = new FileStream(@"C:\Output.pdf", FileMode.Create, FileAccess.Write))
{
var document = new Document(reader.GetPageSizeWithRotation(1));
var writer = PdfWriter.GetInstance(document, fileStream);
document.Open();
for (var i = 1; i <= reader.NumberOfPages; i++)
{
document.NewPage();
var baseFont = BaseFont.CreateFont(BaseFont.HELVETICA_BOLD, BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
var importedPage = writer.GetImportedPage(reader, i);
var contentByte = writer.DirectContent;
contentByte.BeginText();
contentByte.SetFontAndSize(baseFont, 12);
var multiLineString = "Hello,\r\nWorld!".Split('\n');
foreach (var line in multiLineString)
{
contentByte.ShowTextAligned(PdfContentByte.ALIGN_LEFT, line, 200, 200, 0);
}
contentByte.EndText();
contentByte.AddTemplate(importedPage, 0, 0);
}
document.Close();
writer.Close();
}
}
这对我有用，包括使用OutputStream：
PdfReader reader = new PdfReader(new RandomAccessFileOrArray(Request.MapPath("Template.pdf")), null);
Rectangle size = reader.GetPageSizeWithRotation(1);
using (Stream outStream = Response.OutputStream)
{
Document document = new Document(size);
PdfWriter writer = PdfWriter.GetInstance(document, outStream);
document.Open();
try
{
PdfContentByte cb = writer.DirectContent;
cb.BeginText();
try
{
cb.SetFontAndSize(BaseFont.CreateFont(), 12);
cb.SetTextMatrix(110, 110);
cb.ShowText("aaa");
}
finally
{
cb.EndText();
}
PdfImportedPage page = writer.GetImportedPage(reader, 1);
cb.AddTemplate(page, 0, 0);
}
finally
{
document.Close();
writer.Close();
reader.Close();
}
}
这是一种使用不同PDF客户端（Adobe，FoxIt等）中显示的压模和绝对坐标的方法。
public static void AddTextToPdf(string inputPdfPath, string outputPdfPath, string textToAdd, System.Drawing.Point point)
{
//variables
string pathin = inputPdfPath;
string pathout = outputPdfPath;
//create PdfReader object to read from the existing document
using (PdfReader reader = new PdfReader(pathin))
//create PdfStamper object to write to get the pages from reader
using (PdfStamper stamper = new PdfStamper(reader, new FileStream(pathout, FileMode.Create)))
{
//select two pages from the original document
reader.SelectPages("1-2");
//gettins the page size in order to substract from the iTextSharp coordinates
var pageSize = reader.GetPageSize(1);
// PdfContentByte from stamper to add content to the pages over the original content
PdfContentByte pbover = stamper.GetOverContent(1);
//add content to the page using ColumnText
Font font = new Font();
font.Size = 45;
//setting up the X and Y coordinates of the document
int x = point.X;
int y = point.Y;
y = (int) (pageSize.Height - y);
ColumnText.ShowTextAligned(pbover, Element.ALIGN_CENTER, new Phrase(textToAdd, font), x, y, 0);
}
}
这是一种打印图像的方法：从此处获取。在要放置图像的文本上使用不同的图层，并确保使用GetOverContent（）方法。
string oldFile = "FileWithImages.pdf";
string watermarkedFile = "Layers.pdf";
// Creating watermark on a separate layer
// Creating iTextSharp.text.pdf.PdfReader object to read the Existing PDF Document
PdfReader reader1 = new PdfReader(oldFile);
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("Layer", 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.GetOverContent(i);
// Tell the cb that the next commands should be "bound" to this new layer
cb.BeginLayer(layer);
BaseFont bf = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
cb.SetColorFill(BaseColor.RED);
cb.SetFontAndSize(bf, 100);
cb.BeginText();
cb.ShowTextAligned(PdfContentByte.ALIGN_CENTER, "Some random blablablabla...", rect.Width / 2, rect.Height / 2, - 90);
cb.EndText();
// Close the layer
cb.EndLayer();
}
}