This sample shows how to fill forms in existing PDF documents using Docotic.Pdf library.
To change form fields in a PDF, open the document and enumerate its controls using the PdfDocument.GetControls method. Depending on the control Name, provide the value.
If you only need to change a field or two, use the PdfDocument.GetControl method to find the controls by their full or partial names.
You can also import a file in the FDF format with all field values and fill the form in one take.