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DocumentAttachments Class

Summary

Represents a collection of DocumentAttachment objects.

Syntax
C#
C++/CLI
Python
[CollectionDataContractAttribute()] 
public class DocumentAttachments : LeadCollection<DocumentAttachment> 
public: 
   [CollectionDataContractAttribute] 
   ref class DocumentAttachments : LeadCollection<DocumentAttachment^> 
class DocumentAttachments(LeadCollection): 
Remarks

DocumentAttachments manages the attachments of a document. Access it through the Attachments collection of LEADDocument.

DocumentAttachments derives from LeadCollection<T>, and thus can implement System.Collections.ObjectModel.Collection. Use any of the collection methods to add, remove, insert, get, set, and iterate through the attachments.

DocumentAttachments contains a collection of DocumentAttachment objects, each containing the data for a single attachment in the document. The embedded attachments of a document can be read and populated when setting the LoadDocumentOptions.LoadAttachmentsMode property to DocumentLoadAttachmentsMode.AsAttachments during the loading of this document.

DocumentAttachments can also be manually populated by an application program to add or remove attachments to a document.

Refer to Document Attachments for more information.

Example
C#
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Document.Writer; 
 
using Leadtools.Document; 
using Leadtools.Caching; 
using Leadtools.Annotations.Engine; 
using Leadtools.Ocr; 
using Leadtools.Barcode; 
using Leadtools.Document.Converter; 
 
public void AttachmentsExample() 
{ 
   // The PDF document can be one of the following: 
   // 1. Normal PDF without attachments. Has one or more pages and no attachments. 
   // 2. Normal PDF with attachments. Has one or more pages and one or more attachments. 
   // 3. PDF Portfolio. Has a placeholder page and one or more attachments. 
 
   // The value of LoadDocumentOptions.LoadAttachmentsMode affects loading the documents as follows: 
 
   // 1. Normal PDF without attachments: Will not be affected. 
   // 2. Normal PDF with attachments: Number of pages is not affected. 
   //    Number of attachments is: 
   //       LoadAttachmentsMode = None then 0 
   //       LoadAttachmentsMode = AsAttachments then number of attachments found in the document. 
   // 3. PDF Portfolio: Number of pages is: 
   //       LoadAttachmentsMode = None then 1 (the placeholder page) 
   //       LoadAttachmentsMode = AsAttachments then 0 (the document has no pages). 
   //    Number of attachments is: 
   //       LoadAttachmentsMode = None then 0 
   //       LoadAttachmentsMode = AsAttachments then number of attachments found in the document. 
 
   // First, load the document without attachments 
   string pdfFile = Path.Combine(LEAD_VARS.ImagesDir, "Leadtools.pdf"); 
   string outputDirectory = Path.GetDirectoryName(LEAD_VARS.ImagesDir); 
 
   Console.WriteLine($"Loading with DocumentLoadAttachmentsMode.None"); 
   var loadDocumentOptions = new LoadDocumentOptions(); 
   loadDocumentOptions.LoadAttachmentsMode = DocumentLoadAttachmentsMode.None; 
   using (LEADDocument document = DocumentFactory.LoadFromFile(pdfFile, loadDocumentOptions)) 
   { 
      Console.WriteLine(document.GetDocumentFileName()); 
      Console.WriteLine($"Document has {document.Pages.Count} pages"); 
 
      // Find out if the document is portfolio 
      bool isPortfolio = 
         document.Metadata.ContainsKey(LEADDocument.MetadataKey_IsPortfolio) && 
         bool.Parse(document.Metadata[LEADDocument.MetadataKey_IsPortfolio]); 
      Console.WriteLine($"IsPortfolio:{isPortfolio}"); 
 
      // Check that everything is as expected 
 
      // We should have 0 attachments since we did not instruct the toolkit to load these 
      Debug.Assert(document.Attachments.Count == 0); 
 
      // We should have one or more pages regardless of whether the document is PDF portfolio 
      Debug.Assert(document.Pages.Count > 0); 
   } 
 
   // Next, load the document with attachments 
   Console.WriteLine($"Loading with DocumentLoadAttachmentsMode.AsAttachments"); 
   loadDocumentOptions.LoadAttachmentsMode = DocumentLoadAttachmentsMode.AsAttachments; 
   using (LEADDocument document = DocumentFactory.LoadFromFile(pdfFile, loadDocumentOptions)) 
   { 
      document.AutoDeleteAttachmentsFromCache = true; 
             
      Console.WriteLine($"Document has {document.Pages.Count} pages"); 
 
      // Find out if the document is portfolio 
      bool isPortfolio = 
         document.Metadata.ContainsKey(LEADDocument.MetadataKey_IsPortfolio) && 
         bool.Parse(document.Metadata[LEADDocument.MetadataKey_IsPortfolio]); 
      Console.WriteLine($"IsPortfolio:{isPortfolio}"); 
 
      // Check that everything is as expected 
 
      // We may have 0 or more attachments depending on the file 
      Console.WriteLine($"Document has {document.Attachments.Count} attachments"); 
 
      // We should have one or more pages unless this is PDF portfolio, then it will have 0 pages 
      if (isPortfolio) 
      { 
         Debug.Assert(document.Pages.Count == 0); 
      } 
 
      // Extract all the attachments into the output directory 
      foreach (DocumentAttachment attachment in document.Attachments) 
      { 
         // Show info on this attachment 
         Console.WriteLine($"Attachment number {attachment.AttachmentNumber} file name is '{attachment.FileName}', " + 
            $"length is {attachment.FileLength} bytes, and ID is {attachment.DocumentId}, Is Embedded: {attachment.IsEmbedded}"); 
         // Get the attachment file name 
         // This value may not be unique, so combine it with the attachment number 
         string attachmentFileName = $"{attachment.AttachmentNumber}-{attachment.FileName}"; 
         attachmentFileName = Path.Combine(outputDirectory, attachmentFileName); 
 
         // Get the attachment as a stream, we do not want to save it to the cache so pass null for that 
         // DocumentAttachments reference 
         using (Stream attachmentStream = document.Attachments.CreateAttachmentStream(attachment.AttachmentNumber, null)) 
         { 
            if (attachmentStream != null) 
            { 
               // Save it to the output file 
               using (var stream = File.Create(attachmentFileName)) 
               { 
                  document.SaveAttachmentToCache(null); 
                  attachmentStream.CopyTo(stream); 
               } 
            } 
         } 
 
         var saveOptions = new SaveAttachmentToCacheOptions(); 
         saveOptions.AttachmentNumber = 0; 
         saveOptions.UpdateAttachmentDocumentId = true; 
         saveOptions.UploadDocumentOptions = new UploadDocumentOptions(); 
         document.SaveAttachmentToCache(saveOptions); 
 
         // Or load this attachment as a LEADDocument, this might fail if the attachment is not of a valid image 
         // or document format 
         try 
         { 
            Console.WriteLine("Loading as LEADDocument"); 
            var loadAttachmentOptions = new LoadAttachmentOptions(); 
            loadAttachmentOptions.AttachmentNumber = attachment.AttachmentNumber; 
            loadAttachmentOptions.UpdateAttachmentDocumentId = true; 
            using (LEADDocument attachmentDocument = document.LoadDocumentAttachment(loadAttachmentOptions)) 
            { 
               Console.WriteLine($"Success, attachment document mime type is {attachmentDocument.MimeType} and has {attachmentDocument.Pages.Count} pages"); 
            } 
         } 
         catch (Exception ex) 
         { 
            Console.WriteLine($"Error {ex.Message}"); 
         } 
      } 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
} 
Requirements

Target Platforms

Help Version 22.0.2023.4.21
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Leadtools.Document Assembly
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.