//private Action<Func<object, object, int>, bool> _sortFunction; public DataGroupingViewModel() { DataViewOptions options = new DataViewOptions(); options.GroupItemMetadataProvider = new GroupItemMetadataProvider(); options.InlineFilters = true; Projects = new DataView(options); Projects.BeginUpdate(); Projects.SetFilter(MyFilter); Dictionary <string, object> filterArguments = new Dictionary <string, object>( "percentComplete", 0); Projects.SetFilterArgs(filterArguments); LoadData(); SetGrouping(); Projects.EndUpdate(); }