Multiple Select Rows in a datagrid

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C#

I have a datagrid, and the users are able to select multiple rows and
perform an action. This works fine, as I get the rows selected using
something like this:

CurrencyManager xCM =
(CurrencyManager)dgWork.BindingContext[dgWork.DataSource, dgWork.DataMember];
DataView xDV = (DataView)xCM.List;

int RowCount = 0;
foreach(DataRow drow in xDV.Table.Rows)
{
if(dgWork.IsSelected(RowCount))
doAction(drow);
RowCount += 1;
}

the problem is, if the user sorts the grid first by clicking on a row header
then this code is returning me the wrong rows, it returns the row that was at
the position of the selected row BEFORE they filtered. Any way round this ???

Cheers

Steve