pdfGetXFAFormFieldCount

int32_t __stdcall pdfGetXFAFormFieldCount(PPDF IPDF);
const char*    __stdcall pdfGetXFAFormFieldNameA(PPDF IPDF, int32_t Index);
const wchar_t* __stdcall pdfGetXFAFormFieldNameW(PPDF IPDF, int32_t Index);
const char*    __stdcall pdfGetXFAFormFieldNamesA(PPDF IPDF);
const wchar_t* __stdcall pdfGetXFAFormFieldNamesW(PPDF IPDF);

function pdfGetXFAFormFieldCount(const IPDF: PPDF): Integer; stdcall;
function pdfGetXFAFormFieldNameA(const IPDF: PPDF; Index: Integer): PAnsiChar; stdcall;
function pdfGetXFAFormFieldNameW(const IPDF: PPDF; Index: Integer): PWideChar; stdcall;
function pdfGetXFAFormFieldNamesA(const IPDF: PPDF): PAnsiChar; stdcall;
function pdfGetXFAFormFieldNamesW(const IPDF: PPDF): PWideChar; stdcall;

Purpose. Enumerate the leaf field names present in the XFA datasets packet, by count/index or as one newline-joined list.

Description. All three walk the same XfaFieldList: it locates the packet whose name (after any xdp:...: namespace prefix, matched via Pos(':', nm)) equals datasets (LumasXfaPacketIndex), parses it, descends into its <data> child if present (LumasXfaDataNode), and recursively collects every element that has no element children (LumasXfaCollectLeaves) — i.e. every leaf data value, using each leaf's local (unprefixed) XML tag name as the field name. If there is no datasets packet, or it fails to parse, the count is 0 and the name functions return nil/empty. pdfGetXFAFormFieldNames joins every name with #10 (LF) in enumeration order; there is no delimiter escaping, so a field name that itself contains #10 would corrupt the list (XFA element names cannot contain newlines, so this is not reachable in practice).

Parameters.

Return value. pdfGetXFAFormFieldCount: leaf count, 0 if no datasets packet. pdfGetXFAFormFieldName: the leaf's local name, or empty if Index is out of range. pdfGetXFAFormFieldNames: the full #10-joined list.

Remarks. Index here enumerates datasets leaves — a *different* population from the template packet's <field> elements that back pdfGetXFAFormFieldAccess/BorderColor/BorderPresence/BorderWidth below. A name returned here is not guaranteed to also exist as a template field (and vice versa) in a hand-edited or partial XFA document.

C# (P/Invoke)

public static extern int pdfGetXFAFormFieldCount(IntPtr IPDF);