Export a part of page of PDF file to another PDF file

There are couple of ways you can place a part of an existing page to another page:

a) Use the approach shown in ImpositionTest sample (http://www.pdftron.com/pdfnet/samplecode.html#Imposition) to create a form XObject from an existing page then place to another page. You can use a clip path to hide content from the original page outside the given region (see ElementBuilder sample for additional code snippets).

b) Copy element by element to another page. This is show in ElementEdit sample (http://www.pdftron.com/pdfnet/samplecode.html#ElementEdit)

Re: PDF/A, you can use ‘pdftron.PDF.PDFA.PDFACompliance’ (as shown in PDF/A sample). Please keep in mind that PDF/A is technically intended for long term archiving, not editing. It is better to run ‘PDFACompliance’ as the last step (e.g. as part of the archiving process), instead of calling it many times during document creation / editing.