您提供的代码示例甚至输出PDF吗？它看起来像你尝试了许多不同的方式来添加条形码图像，结果是多余的代码混淆了事情......它让我很困惑;-)

无论如何，这是使用PdfStamper实现目标的一种方式，就像你尝试过的那样;示例HTTP Handler(.ashx)：

using System;

using System.IO;

using System.Web;

using iTextSharp.text;

using iTextSharp.text.pdf;

public class addBarcodeWithStamper : IHttpHandler {

public void ProcessRequest (HttpContext context) {

HttpResponse Response = context.Response;

Response.ContentType = "application/pdf";

PdfReader reader = new PdfReader(context.Server.MapPath(PATH_TO_PDF));

/*

* save __one__ instance of barcode image;

* see MakeBarcode() method below

*/

iTextSharp.text.Image barcode = null;

float barcodeWidth = 0;

float barcodeHeight = 0;

using (PdfStamper stamper = new PdfStamper(reader, Response.OutputStream))

{

int n = reader.NumberOfPages;

for (int i = 1; i <= n; i++) {

PdfContentByte cb = stamper.GetOverContent(i);

/*

* re-use image bytes so they are added only __once__

*/

if (barcode == null) {

barcode = MakeBarcode(cb);

barcodeWidth= barcode.Width;

barcodeHeight= barcode.Height;

}

/*

* calculate in case individual page sizes are different

*/

Rectangle rect = stamper.Reader.GetPageSize(i);

float x = (rect.Width - barcodeWidth) / 2;

// modify/remove 10 offset as you see fit

float y = rect.Top - barcodeHeight - 10;

barcode.SetAbsolutePosition(x, y);

cb.AddImage(barcode);

}

}

}

public bool IsReusable {

get { return false; }

}

// ----------------------------------------------------------------------------

public iTextSharp.text.Image MakeBarcode(PdfContentByte cb) {

Barcode128 barcode128 = new Barcode128();

string text2 = "650-M5-013";

barcode128.Code = text2;

barcode128.ChecksumText = true;

return barcode128.CreateImageWithBarcode(cb, null, null);

}

}

显然，您需要将上面的 PATH_TO_PDF 更改为PDF的实际路径 . 还有其他方法可以实现相同的目标 . 例如使用PdfPageEventHelper .