cocoa IKImageBrowserView memory management -

i use ikimagebrowserview in application, if add many photos on application stops working , in profiler see allocated memory high.. need optimize somehow . here browseritem :

public class browseitem : ikimagebrowseritem     { // .....         public override nsstring imagerepresentationtype {             {                 return ikimagebrowseritem.nsurlrepresentationtype;             }         }          public override nsobject imagerepresentation {             {                 return nsurl.fromfilename (_path);             }         } } 

and data source:

public class browsedata : ikimagebrowserdatasource     {         string _arrangeby;         list<browseitem> images;         list<string> dategroup { get; set; }          public override void invoke (action action, double delay)         {             base.invoke (action, delay);         }          public browsedata (string arrangeby) : base ()         {             _arrangeby = arrangeby;             images = new list<browseitem> ();         }          public void fillitems (ienumerable<browseitem> data)         {             if (data != null) {                  switch (_arrangeby) {                 case "month":                     dategroup = data.select (x => x.month).distinct ().tolist ();                     break;                 case "year":                     dategroup = data.select (x => x.year).distinct ().tolist ();                     break;                 default:                     dategroup = data.select (x => x.day).distinct ().tolist ();                     break;                 }                  images = data.tolist ();             }         }            #region required ikimagebrowserdatasource methods          public override nint groupcount (ikimagebrowserview abrowser)         {             return dategroup.count;         }          public override nsdictionary getgroup (ikimagebrowserview abrowser, nint index)         {             var dateheader = dategroup [(int)index];              nsrange range = getindexbygroup ((int)index, dateheader);             #region objects              var rangevalue = nsvalue.fromrange (range);             var stylevalue = nsnumber.fromnint ((int)ikgroupstyle.disclosure);              nsstring titlevalue = new nsstring (dateheader);              #endregion             var objs = new nsobject [] { rangevalue, titlevalue, stylevalue };             var keys = new string [] { grouprangekey, grouptitlekey, groupstylekey };              return nsdictionary.fromobjectsandkeys (objs, keys);         }          public override nint itemcount (ikimagebrowserview abrowser)         {             return images.count;         }          public override iikimagebrowseritem getitem (ikimagebrowserview abrowser, nint index)         {             return images [(int)index];         }          #endregion           public browseitem getitembyindex (int index)         {             return images [index];         }           nsrange getindexbygroup (int index, string dateheader)         {             browseitem item;             var indexofitem = 0; int count = 0;              switch (_arrangeby) {             case "month":                 item = images.first (x => x.month == dateheader);                 count = images.count (x => x.month == dateheader);                 break;             case "year":                 item = images.first (x => x.year == dateheader);                 count = images.count (x => x.year == dateheader);                 break;             default:                 item = images.first (x => x.day == dateheader);                 count = images.count (x => x.day == dateheader);                 break;             }             indexofitem = images.indexof (item);             return getrange (indexofitem, count);         }          nsrange getrange (int index, int count)         {             nsrange range = new nsrange (index, count);             return range;         } } 

profiling results: