How do I programmatically determine the selected rows in a datagrid
The method DataGrid.IsSelected can tell you if a particular row is selected.
So, you could use IsSelected in a loop through all your rows to finds if
multiple rows have been selected. Depending upon the size of your datagrid,
this may be a viable solution. If not, you could track the selections
yourself by monitoring the key actions and the mouse actions. This would be
more work. Thanks to John Hughes to the suggestion to use the dataview.