We are getting an error that is hard to duplicate and occurs at different points. The common occurrences seem to be when our grid is filtered and the user double clicks on a record to do some editing. When they come back from the editing dialog and we try to refresh the grid, this error occurs and the message "Object reference not set to an instance of an object" pops up.
When we run it in debug mode, it does not error out on any specific line of code, so we are having problems figuring out where the error is happening and on what code. From the detail below, its is happening on some type of calculations, but we have no idea how to figure out what its doing at the time or on what calculation. Any ideas? We are using Infragistics 8.3 still
thanks!
See the end of this message for details on invoking just-in-time (JIT) debugging instead of this dialog box.************** Exception Text **************System.NullReferenceException: Object reference not set to an instance of an object. at Infragistics.Win.UltraWinGrid.RefUtils.GetRowCalcIndex(UltraGridRow row, FormulaRowIndexSource rowIndexType) at Infragistics.Win.UltraWinGrid.RefRowIterator.GetNextRow() at Infragistics.Win.UltraWinGrid.RefRowIterator.MoveNext() at Infragistics.Win.UltraWinGrid.RefRowIterator.MoveNext() at Infragistics.Win.UltraWinGrid.RefRowIterator.MoveNext() at Infragistics.Win.UltraWinGrid.RefCellCollection.RefCellCollectionEnumerator.MoveNext() at Infragistics.Win.CalcEngine.RangeCalcInfo.EvaluateNextRow() at Infragistics.Win.CalcEngine.UltraCalcEngine.Evaluate(Int64 ticks) at Infragistics.Win.CalcEngine.UltraCalcEngine.Recalc(Int64 ticks, Boolean isStartOfRecalcOperation) at Infragistics.Win.UltraWinCalcManager.UltraCalcManager.ReCalcInternal(Int64 ticks) at Infragistics.Win.UltraWinCalcManager.UltraCalcManager.ReCalc(Int64 millis) at Infragistics.Win.UltraWinCalcManager.UltraCalcManager.ReCalc() at Infragistics.Win.UltraWinCalcManager.UltraCalcManager.ReCalcSynchronous() at Infragistics.Win.UltraWinCalcManager.UltraCalcManager.VerifyReCalc() at Infragistics.Win.UltraWinCalcManager.UltraCalcManager.DirtyCalc(IUltraCalcReference reference, ValueDirtiedAction action) at Infragistics.Win.UltraWinCalcManager.UltraCalcManager.Infragistics.Win.CalcEngine.IUltraCalcManager.RowsCollectionVisibilityChanged(IUltraCalcReference reference) at Infragistics.Win.UltraWinGrid.ViewStyleBase.OnAfterRowListCreated_ProcessBand(UltraGridBand band) at Infragistics.Win.UltraWinGrid.ViewStyleBase.OnAfterRowListCreated(RowScrollRegion rsr) at Infragistics.Win.UltraWinGrid.ViewStyleBase.RecreateRowList(RowScrollRegion rsr) at Infragistics.Win.UltraWinGrid.RowScrollRegion.RegenerateVisibleRows(Boolean resetScrollInfo) at Infragistics.Win.UltraWinGrid.RowScrollRegion.WillScrollbarBeShown(ScrollbarVisibility assumeColScrollbarsVisible) at Infragistics.Win.UltraWinGrid.RowScrollRegion.PositionScrollbar(Boolean resetScrollInfo) at Infragistics.Win.UltraWinGrid.ScrollRegionBase.SetOriginAndExtent(Int32 origin, Int32 extent) at Infragistics.Win.UltraWinGrid.RowScrollRegion.SetOriginAndExtent(Int32 origin, Int32 extent) at Infragistics.Win.UltraWinGrid.DataAreaUIElement.ResizeRowScrollRegions() at Infragistics.Win.UltraWinGrid.DataAreaUIElement.PositionChildElements() at Infragistics.Win.UIElement.VerifyChildElements(ControlUIElementBase controlElement, Boolean recursive) at Infragistics.Win.UltraWinGrid.DataAreaUIElement.VerifyChildElements(ControlUIElementBase controlElement, Boolean recursive) at Infragistics.Win.UltraWinGrid.DataAreaUIElement.set_Rect(Rectangle value) at Infragistics.Win.UltraWinGrid.UltraGridUIElement.PositionChildElements() at Infragistics.Win.UIElement.VerifyChildElements(ControlUIElementBase controlElement, Boolean recursive) at Infragistics.Win.UltraWinGrid.UltraGridUIElement.VerifyChildElements(ControlUIElementBase controlElement, Boolean recursive) at Infragistics.Win.UIElement.VerifyChildElements(Boolean recursive) at Infragistics.Win.ControlUIElementBase.VerifyIfElementsChanged(Boolean verify, Boolean syncMouseEntered) at Infragistics.Win.ControlUIElementBase.ProcessMouseMoveHelper(Object sender, MouseEventArgs e) at Infragistics.Win.ControlUIElementBase.ProcessMouseMove(Object sender, MouseEventArgs e) at Infragistics.Win.Utilities.ProcessEvent(Control control, ProcessEvent eventToProcess, EventArgs e) at Infragistics.Win.UltraControlBase.OnMouseMove(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseMove(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
Hi,
From the call stack, it looks like the error is occurring on a MouseMove. So the mouse must be moving over a cell in the grid which causes the grid to try to verify it's display and this causes the grid to rebuild it's list of rows which was dirtied at some prior point.
The fact that the grid is blowing up while trying to create the rows is in indication that something is out of synch, which leads me to think that this might be a threading issue.
So what exactly are you doing when you "try to refresh the grid". Is your code using threads anywhere?
Hi Mike,
I had a very similar exception seen today. The only difference being that a summary value was being calculated as shown in the RefSummaryValueCollection in the stack trace. I have to admit that I have seen calculator bugs when using filtering since version 7.2 and have never updated the binding list on the grids except from the GUI thread. Their are five bands in the grid and there is a summary for band 2 that has a formula that references a value in the parent row and the sum of a column in the band 2 rows. There is also a summary for band 0 that is just a simple sum of each column.
I add, remove, or update the binding list periodically by doing an Invoke on the GUI thread and have seen calculator bugs (rarely however). I have removed the calculator as much as possible having even resorted to setting Row.Hidden to true instead of using a filter in previous projects but not this one. I am using version 8.2.20082.2204. The CalcFrequency is set to synchronous. I believe part of the problem is the fact that setting a filter is not a synchronous operation in the Grid so sometimes I have resorted to using EnsureSortedAndFiltered which is synchronous. This exception happened to one of our users so I cannot be exactly sure what they were doing when the exception occurred although as you mentioned above it look like a simple cell activation. Any help or suggestions you can give me would be appreciated. I am wondering at this point if I should resort to always using manual calculations to reduce the chance of an exception like this occuring again. However, I would prefer the bug to be simply fixed as opposed to have to jump through hoops to avoid it.
Here is the call stack: