Spire.PDF for .NET是一款獨立 PDF 控件，用于 .NET 程序中創建、編輯和操作 PDF 文檔。使用 Spire.PDF 類庫，開發人員可以新建一個 PDF 文檔或者對現有的 PDF 文檔進行處理，且無需安裝 Adobe Acrobat。操作簡單，易上手，國產廠商提供優質便捷的技術支持。

近日，Spire.PDF for .NET也迎來了2020年12月更新發布！該版本支持通過外部服務進行數字簽名并且支持設置PDF包中文件的字段并對文件進行排序。此外還增強了PDF轉換到PDF/A 和PDF/A -3b的功能，以及修復了在查找文本中出現的問題，具體更新內容如下：

最新版Spire.PDF for .NET下載

新功能

• 支持通過外部服務進行數字簽名。

  void Sign()
          {
              PdfDocument doc = new PdfDocument();
              doc.LoadFromFile(inputPath);
              //Load the certificate
              X509Certificate2 cert = new X509Certificate2(certPath, passwd);
              CustomPKCS7SignatureFormatter customPKCS7SignatureFormatter = new CustomPKCS7SignatureFormatter(cert);
              PdfSignature signature = new PdfSignature(doc, doc.Pages[0], customPKCS7SignatureFormatter, "signature0");
              signature.Bounds = new RectangleF(new PointF(90, 550), new SizeF(270, 90));
              //Set the dispay mode of graphics, if not set any, the default one will be applied
              signature.GraphicsMode = GraphicMode.SignDetail;
              signature.NameLabel = "Signer:";
              signature.Name = "gary";
              signature.ContactInfoLabel = "ContactInfo:";
              signature.DateLabel = "Date:";
              signature.Date = DateTime.Now;
              signature.LocationInfoLabel = "Location:";
              signature.LocationInfo = "Chengdu";
              signature.ReasonLabel = "Reason: ";
              signature.Reason = "The certificate of this document";
              signature.DistinguishedNameLabel = "DN: ";
              signature.DocumentPermissions = PdfCertificationFlags.AllowFormFill | PdfCertificationFlags.ForbidChanges;
              signature.SignDetailsFont = new PdfFont(PdfFontFamily.TimesRoman, 10f);
              signature.SignNameFont = new PdfFont(PdfFontFamily.Courier, 15);
              signature.SignImageLayout = SignImageLayout.None;
              //Save pdf file.
              doc.SaveToFile(outputPath, Spire.Pdf.FileFormat.PDF);
          }
  
          class CustomPKCS7SignatureFormatter : IPdfSignatureFormatter
          {
              ////// If encapsulate is true, a copy of the message will be included in the signature.
              ///private bool m_encapsulate = true;
  
              ////// The signing certificate.
              ///private X509Certificate2 m_certificate = null;
  
              public Dictionary m_parameters = new Dictionary();
              ////// Parameters for the encoding of the signature.
              /// 1.Key:Filter,String
              /// Required
              /// The name of the preferred signature handler to use when validating this signature.
              /// 2.SubFilter,String
              /// Required
              /// A name that describes the encoding of the signature value.
              /// PDF 1.6 defines the following values for public-key cryptographic signatures: adbe.x509.rsa_sha1, adbe.pkcs7.detached, and adbe.pkcs7.sha1
              /// 3.Cert,X509Certificate2
              /// Required when SubFilter is adbe.x509.rsa_sha1
              ///public Dictionary Parameters
              {
                  get
  
                  { return m_parameters; }
              }
  
              ////// Construct a new instance.
              //////The signing certificate.////// If encapsulate is true, a copy of the message will be included in the signature.
              ///public CustomPKCS7SignatureFormatter(X509Certificate2 certificate)
              {
                  if (null == certificate)
  
                  { throw new ArgumentNullException("certificate"); }
                  m_certificate = certificate;
                  Parameters.Add("Filter", "Adobe.PPKMS");
                  Parameters.Add("SubFilter", m_encapsulate ? "adbe.pkcs7.sha1" : "adbe.pkcs7.detached");
              }
  
              ////// Sign.
              //////The data that contains signature content.///The signaturepublic byte[] Sign(byte[] content)
              {
                  CmsSigner cmsSigner = new CmsSigner(m_certificate);
                  SHA1 sha1 = SHA1.Create();
                  SignedCms signedCms = new SignedCms(new ContentInfo(m_encapsulate ? sha1.ComputeHash(content) : content), !m_encapsulate);
                  signedCms.ComputeSignature(cmsSigner, true);
                  byte[] result = signedCms.Encode();
                  return result;
              }
          }

• 支持設置PDF包中文件的字段并對文件進行排序。

  string[] files = Directory.GetFiles(@"files");
  string inputFile = @"input.pdf";
  string outputFile = @"result.pdf";
  using (PdfDocument doc = new PdfDocument(inputFile))
  {
      //添加字段
      doc.Collection.AddCustomField("No", "序號", Spire.Pdf.Collections.CustomFieldType.NumberField);
      doc.Collection.AddFileRelatedField("FileName", "文件名稱", Spire.Pdf.Collections.FileRelatedFieldType.FileName);
      doc.Collection.AddFileRelatedField("Desc", "文件描述", Spire.Pdf.Collections.FileRelatedFieldType.Desc);
      doc.Collection.AddFileRelatedField("CreateDate", "創建時間", Spire.Pdf.Collections.FileRelatedFieldType.CreationDate);
      doc.Collection.AddFileRelatedField("ModDate", "修改時間", Spire.Pdf.Collections.FileRelatedFieldType.ModDate);
      doc.Collection.AddFileRelatedField("FileSize", "文件大小", Spire.Pdf.Collections.FileRelatedFieldType.Size);
      doc.Collection.AddCustomField("FileType", "文件類型", Spire.Pdf.Collections.CustomFieldType.TextField);
      doc.Collection.AddCustomField("FileDate", "自定義時間", Spire.Pdf.Collections.CustomFieldType.DateField);
  
      //根據字段對附件排序
      doc.Collection.Sort(new string[] { "No", "fileName", "Desc", "CreateDate", "ModDate", "FileSize", "FileType", "FileDate" }, new bool[] { false, true, true, true, true, true, true, true });
      for (int i = 0; i < files.Length; i++) { PdfAttachment attachment = new PdfAttachment(files[i]); doc.Collection.AddAttachment(attachment); } int n = 1; //設置字段值 foreach (PdfAttachment att in doc.Collection.AssociatedFiles) { att.SetFieldValue("No", n); att.Description = n + "文件描述"; att.SetFieldValue("FileDate", DateTime.Today); att.SetFieldValue("FileType", n + "文件"); n++; } doc.SaveToFile(outputFile, FileFormat.PDF); doc.Dispose(); }

• 支持添加附件時，指定文檔關系。

  PdfDocument doc = new PdfDocument();
  doc.LoadFromFile(inputPath);
  PdfAttachment attachment = new PdfAttachment(attachmentPath);
  doc.Attachments.Add(attachment,doc,Spire.Pdf.General.PdfAttachmentRelationship.Alternative);
  doc.SaveToFile(outputPath);

• 支持在指定區域內查找文本。

  PdfDocument pdf = new PdfDocument();
  pdf.LoadFromFile(inputFile, FileFormat.PDF);
  RectangleF rctg = new RectangleF(0, 0, 200, 100);
  PdfTextFindCollection findCollection = pdf.Pages[0].FindText(rctg, "DEPOSIT", TextFindParameter.WholeWord);
  PdfTextFindCollection findCollectionOut = pdf.Pages[0].FindText(rctg, "agreement", TextFindParameter.WholeWord);
  foreach (PdfTextFind find in findCollection.Finds)
  { find.ApplyHighLight(Color.Green); }
  foreach (PdfTextFind findOut in findCollectionOut.Finds)
  { findOut.ApplyHighLight(Color.Yellow); }
  pdf.SaveToFile(outputFile, FileFormat.PDF);

Bug修復

• 修復了轉換含附件的PDF到PDF/A-3b不符合規范的問題。
• 修復了轉換含動作的PDF到PDF/A不符合規范的問題。
• 修復了獲取書簽時程序掛起的問題。
• 調整了.NET Standard平臺下的PdfTrueTypeFont類的初始化方法。
• 修復了注釋無法刪除的問題。
• 修復了添加上下標導致字符間距不正確的問題。
• 修復了查找文本拋“NullReferenceException”的問題。
• 修復了查找文本失敗的問題。