how to unselect a devexpress data grid row when we click with ctrl+ mouse left button wpf

how to unselect a devexpress data grid row when we click with ctrl+ mouse
left button wpf

I have a devexpress data grid with data. I am able to select multiple rows
and on button click I am unselecting all the rows perfectly. but the
problem is I am unable to deselect the row with ctrl+mouse left click.
actually the row is getting deselected, when I check the visiblerowcount
value, but in the UI it is still showing as selected row.
How can I do unselection? this is the code for selecting all the rows of
my grid
MyGrid.TableView.SelectAll();
SelectedRecords.Text = "" + MyGridVisibleRowCount;
and for unselection all the rows on button click I am doing in this way
MyGrid.ClearSelection();
MyGrid.View.FocusedRowHandle = -1;
SelectedRecords.Text = "" + 0;
any help highly appericated.
Thanks Ganesh