Is it possible to pass an XFA to a PDF form in order to populate the PDF form using PDFTron library? If not, are there any alternatives? Any other suggestions?
PDFNet SDK currently offers a limited high-level support for XFA (i.e.Adobe LiveCycle) forms. Besides LiveCycle we are not aware of any third party product with complete XFA support. XFA is a proprietary Adobe extension; it is not allowed as part of PDF/A and there is a movement to remove XFA references from ISO 32000-2.
As a possible solution your users could re-save PDF document with AcroForm/PDF compatibility in Adobe LifeCycle-Designer. After resaving the document using LifeCycle- Designer you will be able to properly render and process the document using PDFNet.
For more background and some thoughts on XFA Forms please see:
Please keep in mind that you can use PDFNet low-level APIs to extract/edit XFA data from PDF files (e.g. see https://groups.google.com/d/msg/pdfnet-sdk/zgoiXfCf_bU/ktXNzkpTspkJ). It is also possible to implement custom controls on top of PDFViewCtrl, so technically you could implement your own XFA layer on top of PDFNet.