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What is the difference between PdfLoadedDocument and PdfDocument classes

I am trying to do a proof on concept where I take a few uploaded PDFs and merge them with a local file then set  form value(s), flatten the form, run OCR and then encrypt the PDF.

here is my sample code :

 Stream stream1 = File1.PostedFile.InputStream;
                Stream stream2 = File2.PostedFile.InputStream;

                //Load the documents as streams
                PdfLoadedDocument doc1 = new PdfLoadedDocument(stream1);
                PdfLoadedDocument doc2 = new PdfLoadedDocument(stream2);
                PdfLoadedDocument doc3 = new PdfLoadedDocument(Server.MapPath("~/PDFTemplates/My_PDF_with_fields.pdf"));

                PdfLoadedForm form = doc3.Form;

                // fill the fields from the first page
                (form.Fields["::agency_name::"] as PdfLoadedTextBoxField).Text = "test name";
                object[] dobj = { doc1, doc2, doc3 };
                PdfDocument doc = new PdfDocument();
                PdfDocument.Merge(doc, dobj);
                doc.Form.Flatten = true;

                OCRProcessor processor = new OCRProcessor();
                //Language to process the OCR
                processor.Settings.Language = Languages.English;
                //Process OCR by providing loaded PDF document, Data dictionary and language
                processor.PerformOCR(doc, Server.MapPath("/bin/Tessdata"));

Is there a way to convert a PdfDocument  to  a PdfLoadedDocument so i no longer get:

cannot convert from 'Syncfusion.Pdf.PdfDocument' to 'Syncfusion.Pdf.Parsing.PdfLoadedDocument'

5 Replies

KC Karthikeyan Chandrasekar Syncfusion Team January 10, 2014 09:14 AM UTC

Hi Eric,

Thank you for your interest in Syncfusion Products.


We can able to convert PdfDocument into PdfLoadedDocument, please use the code snippet below.


            MemoryStream pdfGenerated = new MemoryStream();

            PdfDocument.Merge(doc, dobj);

            doc.Form.Flatten = true;




            PdfLoadedDocument ldDoc = new PdfLoadedDocument(pdfGenerated);


Please let us know if you need any further assistance.



ER Eric Rosenblum January 20, 2014 08:05 PM UTC


Thank you for the reply.

Do you also have a code example for importing (and exporting)  an XFDF stream (or string) data into a PDF to populate its form data and an example of looping through the loaded form names and values?

For example I may want to import the entire XFDF, then set a few fields manually, possibly loop through the form names and values, possibly flatten the form, and possibly export the resultant XFDF.



KC Karthikeyan Chandrasekar Syncfusion Team January 22, 2014 04:26 AM UTC

HI Eric,

Thank you for your interest in Syncfusion Products.


We can able to import and export the XFDF data to Pdf forms please use the below code snippet:



             PdfLoadedDocument doc = new PdfLoadedDocument("SourceForm.pdf");

             PdfLoadedForm form = doc.Form;

             MemoryStream stream = new MemoryStream();

             form.ExportData(stream, DataFormat.XFdf, "SourceForm.pdf");



             PdfLoadedDocument doc = new PdfLoadedDocument("SourceForm.pdf");

             PdfLoadedForm form = doc.Form;           

             form.ImportData("ImportData.XFdf",DataFormat.XFdf, false);



Please refer the below link to fill the PDF from fields manually.



Please let us know if you have any concern.




ER Eric Rosenblum September 24, 2015 08:01 PM UTC

Lets say I have an XFDF string in memory, not on disk, how I use the ImportData method?   I dont see any overloaded method to pass a stream or XML?

form.ImportData("ImportData.XFdf",DataFormat.XFdf, false);

AS Abirami Selvan Syncfusion Team September 25, 2015 01:11 PM UTC

Hi  Eric,

We have an overload method to pass the XFDF file as  stream to import into an existing PDF document.
Please refer to the following code snippet:

// Load the existing form

PdfLoadedForm form = doc.Form;

// Load the FDF file

FileStream stream = new FileStream("ImportFDF.xfdf", FileMode.Open);

// Import the FDF stream
form.ImportDataXFDF(stream, true);

We have created the sample for your reference in the below link:

Please try  this and let us know if you have any further assistance.


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