Introduction
PDF/A is a format based on PDF and designed for long-term data archiving. The profound description of this standard can be found on Wikipedia or in ISO 19005-1, ISO 19005-2, ISO 19005-3 documents. We won’t dive into all specifics here and will limit ourselves to a brief description of its core differences.
The main requirement a PDF/A document should conform to is a self-containment. That is, all the data required to display this document should be embedded, including:
- Fonts, including standard 14 PDF fonts, preferably in a form of font subsets if not all glyphs are used
- Output intent colorspace in a form of ICC profile
- Images, if image colorspace is different from the output intent then conversion is required
- Forms fields appearance
Many features allowed in PDF are prohibited in PDF/A, for example:
- Soft masks and transparency groups
- Some types of annotations
- Links to external docs
- Embedded files
The code
Let’s create the simple “Hello World!” PDF/A document using Apitron PDF Kit for .NET and check its properties. Functions below demonstrate how to do it using both supported APIs.
Fixed layout API:
///<summary>
/// Creates PDF/A document using Fixed layout API.
///</summary>
privatevoid CreatePDFADocumentUsingFixedLayoutAPI()
{
// create document object and indicate PDF/A support
FixedDocument doc = newFixedDocument(PdfStandard.PDFA);
// create text object, set its font and content
TextObject textObject = newTextObject(StandardFonts.Helvetica,14);
textObject.AppendText("Hello world! PDF/A document created by Apitron PDF Kit for .NET.");
// create new page and append text object created above
Page page = newPage(Boundaries.A4);
page.Content.Translate(10,820);
page.Content.AppendText(textObject);
doc.Pages.Add(page);
// save PDF/A document
using (Stream stream = File.Create("pdfa_doc.pdf"))
{
doc.Save(stream);
}
}
Flow layout API:
///<summary>
/// Creates PDF/A document using Flow layout API.
///</summary>
privatevoid CreatePDFADocumentUsingFlowLayoutAPI()
{
ResourceManager resourceManager = newResourceManager();
// create document and set margin
FlowDocument doc = newFlowDocument(){Margin = newThickness(10)};
// create text block and append to document
TextBlock textBlock = newTextBlock("Hello world! PDF/A document created by Apitron PDF Kit for .NET.");
doc.Add(textBlock);
// save as PDF/A document
using (Stream stream = File.Create("pdfa_doc.pdf"))
{
doc.Write(stream, resourceManager, newPageBoundary(Boundaries.A4), PdfStandard.PDFA);
}
}
Functions above produce identical PDF files looking as one shown below:
 |
Pic. 1 PDF/A document produced by Apitron PDF Kit |
On the left panel you can see that produced document successfully passes PDF/A standard conformance validation.
Conclusion
Apitron PDF Kit for .NET library is available by the following link. It can be used to create cross platform PDF processing applications and is suitable for many PDF generation scenarios. Create Windows, Android and iOS (Xamarin), MONO apps, web or cloud solutions. It’s truly cross-platform and we constantly improve it by adding new features and providing updates.
Check out our free bookdescribing the API and containing ready to use code snippets. Read our blog or contact us if you have any questions.
Downloadable version of this article can be found by the following link [PDF].
Downloadable version of this article can be found by the following link [PDF].