NullReferenceException

[Lori S. Pearsall]

I have a Combobox column in a GDBG. In the CurrentCellValidating event, there''s a particular case where I want to cancel the change. So I execute the following code :

grid.CurrentCell.CancelEdit(); e.Cancel = true;

Visually, the column changes back to the previous value. However, when I then tab out of the column, I get the following error :

-------
catched at Syncfusion.Windows.Forms.Grid.GridCurrentCell.Validate() in :line 0
An unhandled exception of type ''System.NullReferenceException'' occurred in syncfusion.grid.dll

Additional information: Object reference not set to an instance of an object.

catched at Syncfusion.Windows.Forms.Grid.GridCurrentCell.ConfirmChanges(Boolean closeDropDown) in :line 0
catched at Syncfusion.Windows.Forms.Grid.GridCurrentCell.Deactivate(Boolean discardChanges) in :line 0

Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object.
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.Deactivate(Boolean discardChanges)
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.MoveTo(Int32 rowIndex, Int32 colIndex, GridSetCurrentCellOptions options, Boolean discardChanges)
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.MoveTo(Int32 rowIndex, Int32 colIndex, GridSetCurrentCellOptions options)
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.InternalMove(GridDirectionType direction, Int32 num, GridSetCurrentCellOptions options)
at Syncfusion.Windows.Forms.Grid.GridSelectCellsMouseController.GridCurrentCellExternalMove(GridDirectionType direction, Int32 num, Boolean extendSelection)
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.Move(GridDirectionType direction, Int32 num, Boolean extendSelection, Boolean wrapCell)
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.Move(GridDirectionType direction, Int32 num, Boolean extendSelection)
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.MoveRight(Int32 num, Boolean extendSelection)
at Syncfusion.Windows.Forms.Grid.GridCurrentCell.MoveRight()
at Syncfusion.Windows.Forms.Grid.GridControlBase.OnKeyDown(KeyEventArgs e)
at Syncfusion.Windows.Forms.Grid.GridDataBoundGrid.OnKeyDown(KeyEventArgs e)
at System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m)
at Syncfusion.Windows.Forms.Grid.GridControlBase.ProcessKeyEventArgs(Message& m)
at System.Windows.Forms.Control.ProcessKeyMessage(Message& m)
at Syncfusion.Windows.Forms.Grid.GridControlBase.ProcessKeyMessage(Message& m)
at System.Windows.Forms.Control.WmKeyChar(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at Syncfusion.Windows.Forms.ScrollControl.WndProc(Message& msg)
at Syncfusion.Windows.Forms.Grid.GridControlBase.WndProc(Message& msg)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.ComponentManager.System.Windows.Forms.UnsafeNativeMethods+IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(Form mainForm)
at TimelineManager.TimelineInterface.Main() in c:\moss adams\holman - timeline\development\timelinemanager\timelineinterface.cs:line 1392The program ''[3308] TimelineManager.exe'' has exited with code 0 (0x0).
-------

I''ve examined the CellValue after the e.Cancel = true statement, and it''s not null. Since this error isn''t occurring in my code, what do I need to start looking for? I''m not sure what it thinks is null.

[Administrator]

Instead of calling grid.CurrentCell.CancelEdit();, try this code to see if it avoids this problem.

GridCurrentCell cc = grid.CurrentCell;
cc.Renderer.Control.Text = grid[cc.RowIndex, cc.ColIndex].Text;
e.Cancel = true;