PDFDocMemory

1//
2// Copyright (c) 2001-2021 by PDFTron Systems Inc. All Rights Reserved.
3//
4
5using System;
6using System.IO;
7using pdftron;
8using pdftron.Common;
9using pdftron.Filters;
10using pdftron.SDF;
11using pdftron.PDF;
12
13// The following sample illustrates how to read/write a PDF document from/to 
14// a memory buffer.  This is useful for applications that work with dynamic PDF
15// documents that don't need to be saved/read from a disk.
16using NUnit.Framework;
17
18namespace MiscellaneousSamples
19{
20	[TestFixture]
21	public class PDFDocMemoryTest
22	{
23		
24		[Test]
25		public static void Sample()
26		{
27
28			// Relative path to the folder containing test files.
29			const string input_path =  "TestFiles/";
30
31			try  
32			{
33				// Read a PDF document from a stream or pass-in a memory buffer...
34				FileStream istm = new FileStream(Utils.GetAssetTempFile(input_path + "tiger.pdf"), FileMode.Open, FileAccess.Read);
35				using (PDFDoc doc = new PDFDoc(istm))
36				using (ElementWriter writer = new ElementWriter())
37				using (ElementReader reader = new ElementReader())
38				{
39					doc.InitSecurityHandler();
40
41					int num_pages = doc.GetPageCount();
42
43					Element element;
44
45					// Perform some document editing ...
46					// Here we simply copy all elements from one page to another.
47					for(int i = 1; i <= num_pages; ++i)
48					{
49						Page pg = doc.GetPage(2 * i - 1);
50
51						reader.Begin(pg);
52						Page new_page = doc.PageCreate(pg.GetMediaBox());
53						doc.PageInsert(doc.GetPageIterator(2*i), new_page);
54
55						writer.Begin(new_page);
56						while ((element = reader.Next()) != null) 	// Read page contents
57						{
58							writer.WriteElement(element);
59						}
60
61						writer.End();
62						reader.End();
63					}
64
65					doc.Save(Utils.CreateExternalFile("doc_memory_edit.pdf"), SDFDoc.SaveOptions.e_remove_unused);
66
67					// Save the document to a stream or a memory buffer...
68					using (FileStream ostm = new FileStream(Utils.CreateExternalFile("doc_memory_edit.txt"), FileMode.Create, FileAccess.Write)) {
69						doc.Save(ostm, SDFDoc.SaveOptions.e_remove_unused);
70					}
71
72					// Read some data from the file stored in memory
73					reader.Begin(doc.GetPage(1));
74					while ((element = reader.Next()) != null) {
75						if (element.GetType() == Element.Type.e_path)
76							Console.Write("Path, ");
77					}
78					reader.End();
79
80                    Console.WriteLine("");
81                    Console.WriteLine("");
82                    Console.WriteLine("Done. Result saved in doc_memory_edit.pdf and doc_memory_edit.txt ...");
83				}
84			}
85			catch (PDFNetException e)
86			{
87				Console.WriteLine(e.Message);
88				Assert.True(false);
89			}
90		}
91	}
92}