This thread already mentions how to calculate totals from the whole data or the filtered/paged.
Whole:
orders.Sum(o => o.Freight)
Filtered:
ordersGrid.View.Sum(o => o.Freight)
This thread already mentions how to calculate totals from the whole data or the filtered/paged.
Whole:
orders.Sum(o => o.Freight)
Filtered:
ordersGrid.View.Sum(o => o.Freight)