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