Fields IndexOf Function. Determines the index of a specific item. ABCpdf .NET PDF Library. From ABCpdf .net previous page next page IndexOf Function Determines the index of a specific item. Syntax [C#]int IndexOf(Field value) [Visual Basic]Function IndexOf(value As Field) As Integer Params Name Description value The object to locate in the collection. return If found, the index of value, otherwise -1. Notes Determines the index of a specific item in the collection. Example None. previous page start next page