解决方法
加密您的PDF文档.简单的HTTP处理程序工作示例让您开始：
<%@ WebHandler Language="C#" Class="lockPdf" %>
using System;
using System.Web;
using iTextSharp.text;
using iTextSharp.text.pdf;
public class lockPdf : IHttpHandler {
public void ProcessRequest (HttpContext context) {
HttpServerUtility Server = context.Server;
HttpResponse Response = context.Response;
Response.ContentType = "application/pdf";
using (Document document = new Document()) {
PdfWriter writer = PdfWriter.GetInstance(
document,Response.OutputStream
);
writer.SetEncryption(
// null user password => users can open document __without__ pasword
null,// owner password => required to __modify__ document/permissions
System.Text.Encoding.UTF8.GetBytes("ownerPassword"),/*
* bitwise or => see iText API for permission parameter:
* http://api.itextpdf.com/itext/com/itextpdf/text/pdf/PdfWriter.html
*/
PdfWriter.ALLOW_PRINTING
| PdfWriter.ALLOW_COPY,// encryption level also in documentation referenced above
PdfWriter.ENCRYPTION_AES_128
);
document.Open();
document.Add(new Paragraph("hello world"));
}
}
public bool IsReusable { get { return false; } }
}
内联评论应该是不言自明的.见PdfWriter documentation.
您还可以使用使用PdfEncryptor class的PdfReader对象加密PDF文档.换句话说,您还可以执行此操作(未测试)：
PdfReader reader = new PdfReader(INPUT_FILE);
using (MemoryStream ms = new MemoryStream()) {
using (PdfStamper stamper = new PdfStamper(reader,ms)) {
// add your content
}
using (FileStream fs = new FileStream(
OUTPUT_FILE,FileMode.Create,FileAccess.ReadWrite))
{
PdfEncryptor.Encrypt(
new PdfReader(ms.ToArray()),fs,null,System.Text.Encoding.UTF8.GetBytes("ownerPassword"),PdfWriter.ALLOW_PRINTING
| PdfWriter.ALLOW_COPY,true
);
}
}
