My application is an addin to Excel, and during each operation (like drag
drop a string from external source to a cell in Excel)we do
ExcelApplicationObject.Undo() and then try to get Excel cell value and store
that previous cell value in cache for later use - but at one instance (like
when we hold "Shift" key and drag drop a normal string to a excel cell) we
are seeing "Exception from HRESULT: 0x800A01A8" exception and I dont see any
wrong in my code. Please help me why I am seeing this error.

Below is the code snippet...

oldValue = string.Empty;
newValue = string.Empty;
Excel1.Range currentRange = r;
if (r.Cells.Value2 != null)
{
newValue = Utility.GetCellValue (r) ;
}

m_app.Undo();

if (r.Cells.Value2 != null) // getting exception at this point, and r is
not null.
{
oldValue = Utility.GetCellValue (r);
}

r = currentRange;


--
Aruna