Preserving PDF/A compliance after PDF editing

[Support]

Q:

 

I'm trying to add an e_signature field to a valid PDF/A document.

Using the following code:

Field sigField = pdfDocument.FieldCreate("Signature1", Field.Type.e_signature);

Widget widgetAnnot = Widget.Create(pdfDocument.GetSDFDoc(), new Rect(85, 458, 503, 502), sigField);

pdfPage.AnnotPushBack(widgetAnnot);

widgetAnnot.SetPage(pdfPage);

checking resulting PDF with a customer's pdf/a validation tool I get:

The appearance dictionary doesn't contain an entry.

The document does not conform to the requested standard.

The document contains annotations or form fields with ambiguous or without appropriate appearances.

I tried to use annotation.SetAppereance() but I got a lot of different validation error.

My goal is to add an e_signature field to PDF/A document preserving PDF/A compliance: is there a sample code to do this? 

I check SDK samples but I can't find this case..

Another question: shall I convert modified pdf in pdf/a each time that I add a widget or if initial pdf is PDF/a could I avoid re-conversion?

 

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A:

 

If you look at the InteractiveFormsTest sample there is a call to doc.RefreshFieldAppearances(), 

I think this will correct the issue. If not, please read the note just before the call to 

doc.RefreshFieldAppearances(), as it explains some of the options regarding appearances.

http://www.pdftron.com/pdfnet/samplecode/InteractiveFormsTest.cs

 

 

Alternatively you can use ‘pdftron.PDF.PDFA.PDFACompliance’ on the generated document. This will 

convert a generic PDF to PDF/A (or will resolve the remaining PDF/A compatibility issues). 

Please keep in mind that PDF/A files are intended for editing so you should minimize (or 

eliminate) further editing once the file is normalized to PDF/A.