Returns the item that is associated to the filename given as a parameter.
Uses the SortedDictionary that is maintained within the FileList to
determine whether the p_FileName is contained as a key if the AllowDuplicates property is set to true.
Otherwise it iterates through the list of items in O(n) to find the first entry.
- p_FileName (String)
- The filename to search for through the dictionary
null, if the item is not in the list otherwise a reference to the item