I'm trying to set the Top N options for a group using the CR .NET API. The group already has a Top N sort defined for it in the report file.
My C# code looks like this:
public void SetTopNOptions(bool top, int nGroups, bool discardOthers)
ISCRSort groupSort = reportDocument.ReportClientDocument.DataDefController.DataDefinition.Sorts[groupIndex];
TopNSort topNSort = new TopNSort();
topNSort.Direction = top ? CrSortDirectionEnum.crSortDirectionTopNOrder : CrSortDirectionEnum.crSortDirectionBottomNOrder;
topNSort.DiscardOthers = discardOthers;
topNSort.NIndividualGroups = nGroups;
topNSort.SortField = groupSort.SortField;
This succeeds the first time, and I can show the report in a preview control & it displays the correct number of groups.
However, the second time I call this on the same ReportDocument I get a NullReferenceException when I call Modify. I think this is due to the fact that groupSort.SortField is null (and therefore so is topNSort.SortField).
Interestingly, if I try to do this using the Engine classes, I get the same behaviour!
SortField sortField = reportDocument.DataDefinition.SortFields[groupIndex];
TopBottomNSortField tbnsf = sortField as TopBottomNSortField;
if (tbnsf != null)
tbnsf.NumberOfTopOrBottomNGroups = nGroups;
The first time through this code succeeds, but the second time throws a NullReferenceError. I wouldn't be surprised if the Engine-level code is doing something pretty similar to the RAS code above.
Anyway, please repro and file a bug report.
- rick cameron