itextsharp去掉PDF加密

1 using iTextSharp.text.pdf;
2 using iTextSharp.text;
3 using System.IO;

 1  　　　　/// <summary>
 2         /// 将去掉PDF的加密
 3         /// </summary>
 4         /// <param name="sourceFullName">源文件路径(如：D:\old.pdf)</param>
 5         /// <param name="newFullName">目标文件路径(如:D:\new.pdf)</param>
 6         private static void deletePDFEncrypt(string sourceFullName, string newFullName)
 7         {
 8             if (string.IsNullOrEmpty(sourceFullName) || string.IsNullOrEmpty(newFullName))
 9             {
10                 throw new Exception("源文件路径或目标文件路径不能为空或null.");
11             }
12             //Console.WriteLine("读取PDF文档");
13             try
14             {
15                 // 创建一个PdfReader对象
16                 PdfReader reader = new PdfReader(sourceFullName);
17                 PdfReader.unethicalreading = true;
18                 // 获得文档页数
19                 int n = reader.NumberOfPages;
20                 // 获得第一页的大小
21                 Rectangle pagesize = reader.GetPageSize(1);
22                 float width = pagesize.Width;
23                 float height = pagesize.Height;
24                 // 创建一个文档变量
25                 Document document = new Document(pagesize, 50, 50, 50, 50);
26                 // 创建该文档
27                 PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(newFullName, FileMode.Create));
28                 // 打开文档
29                 document.Open();
30                 // 添加内容
31                 PdfContentByte cb = writer.DirectContent;
32                 int i = 0;
33                 int p = 0;
34                 while (i < n)
35                 {
36                     document.NewPage();
37                     p++;
38                     i++;
39                     PdfImportedPage page1 = writer.GetImportedPage(reader, i);
40                     cb.AddTemplate(page1, 1f, 0, 0, 1f, 0, 0);
41                 }
42                 // 关闭文档
43                 document.Close();
44             }
45             catch (Exception ex)
46             {
47                 throw new Exception(ex.Message);
48             }
49         }