Extracts an embedded file (attachment) from a PDF document file and saves it to disk.
public static void ExtractEmbeddedFile(string fileName,string password,int fileNumber,string outputFileName)
fileName
Name of the owner PDF document file.
password
The password to use when loading this PDF file (if the file is encrypted); otherwise, use null.
fileNumber
Embedded file number. This value must be between 1 and the total number of embedded files in the owner PDF document.
outputFileName
Name of the file that will contain the embedded file binary data.
ExtractEmbeddedFile is used to extract one embedded file (attachment) from a PDF document.
The attachment to extract is identified using the fileNumber variable which must be a value between 1 (for the embedded file) and the total number of attachments in the file (for the last embedded file).
Use GetEmbeddedFileCount to quickly get the number of embedded files in a PDF document.
To find more information regarding the embedded files before extracting them (such as the file name and size), the application can perform the following:
using Leadtools.WinForms;using Leadtools;using Leadtools.Codecs;using Leadtools.Controls;using Leadtools.Drawing;using Leadtools.ImageProcessing;using Leadtools.Pdf;using Leadtools.Svg;public static void ExtractAttachmentsAndStitch(string inputFileName, string outputFileName){File.Delete(outputFileName);// Get the number of embedded files (attachments) in the input fileint attachmentCount = PDFFile.GetEmbeddedFileCount(inputFileName, null);// If the file does not have any attachments we are doneif (attachmentCount == 0){File.Copy(inputFileName, outputFileName, true);return;}// To convert attachment files that are not PDFvar rasterCodecs = new RasterCodecs();rasterCodecs.ThrowExceptionsOnInvalidImages = false;var tempFiles = new List<string>();// Now, extract all the attachmentsfor (int attachmentNumber = 1; attachmentNumber <= attachmentCount; attachmentNumber++){// Extract this attachment to a temporary filestring tempFile = Path.GetTempFileName();PDFFile.ExtractEmbeddedFile(inputFileName, null, attachmentNumber, tempFile);// If attachment is not PDF, convert itRasterImageFormat format;int pageCount;using (CodecsImageInfo info = rasterCodecs.GetInformation(tempFile, true)){format = info.Format;pageCount = info.TotalPages;}if (format == RasterImageFormat.Unknown){// We do not know what to do with this attachment, log and ignore itConsole.WriteLine("Could not convert attachment file to PDF, ignoring");File.Delete(tempFile);}else if (format != RasterImageFormat.RasPdf){// Simple conversion using RasterImage.// TODO for the Example: A better way is to use the DocumentConverter to get true document conversion with all the// options availablestring tempPdfFile = Path.GetTempFileName();for (int pageNumber = 1; pageNumber <= pageCount; pageNumber++){using (RasterImage image = rasterCodecs.Load(tempFile, pageNumber)){rasterCodecs.Save(image, tempPdfFile, RasterImageFormat.RasPdfJpeg422, 0, 1, -1, -1, CodecsSavePageMode.Append);}}File.Copy(tempPdfFile, tempFile, true);File.Delete(tempPdfFile);tempFiles.Add(tempFile);}else{// TODO for the Example: Check if this file is PDF with attachments and call the function recursively.tempFiles.Add(tempFile);}}// Time to generate the final document, first the pages from the original document// Did we extract/convert any attachments?if (tempFiles.Count > 0){// Note that if the original document is PDF portfolio, then it does not contain real pages. Just a placeholder that should be ignoredif (!PDFFile.IsPortfolio(inputFileName, null)){PDFFile file = new PDFFile(inputFileName);file.MergeWith(tempFiles.ToArray(), outputFileName);}else{// This is portfolio, so we will ignore the original file and just merge the attachmentsstring firstFile = tempFiles[0];tempFiles.RemoveAt(0);PDFFile file = new PDFFile(firstFile);file.MergeWith(tempFiles.ToArray(), outputFileName);File.Delete(firstFile);}}else{// No, just copy the original file overFile.Copy(inputFileName, outputFileName, true);}// Clean upforeach (string tempFile in tempFiles)File.Delete(tempFile);rasterCodecs.Dispose();}