Supported Form Fields


ComPDFKit PDF SDK supports all form types specified by the PDF specification (such as text boxes, checkboxes, radio buttons, drop-down lists, pushbuttons, and signatures).


CPDFWidgetAnnotation is the base class for all form fields, and CPDFWidgetAnnotation is subclass for CPDFAnnotation. A CPDFWidgetAnnotation object by itself is not useful, only subclasses (CPDFButtonWidgetAnnotation, CPDFChoiceWidgetAnnotationCPDFTextWidgetAnnotation, CPDFSignatureWidgetAnnotation) are interesting. In parsing a PDF, however, any unknown or unsupported form fields will be represented as this base class.


We have to differentiate between field types and annotation objects:


Type Annotation Object
Check, Radio, and Push Buttons CPDFButtonWidgetAnnotation
List and Combo Boxes CPDFChoiceWidgetAnnotation
Text CPDFTextWidgetAnnotation
Signatures CPDFSignatureWidgetAnnotation