Represents types of the PdfFields.
Field is a PdfDropdownField that may be accompanied by an editable text box in which the user can type a value other than the predefined choices.
Field is a scrollable PdfListBoxField.
Field is a PdfRadioButtonField in a set of related buttons that can each be on or off. Typically, at most one radio button in a set may be on at any given time, and selecting any one of the buttons automatically deselects all the others. (There are exceptions to this rule, as noted in "Radio Buttons").
Field is a PdfTextField which is a box or space for text fill-in data typically entered from a keyboard.
Field is unknown and currently not supported.