You can use the sender object:
private void OrderProductGrid_RowEditEnded(object sender, DataGridRowEditEndedEventArgs e)
{
Button wichButton = sender as Button;
if (wichButton != null)
{
}
if (ValidateonSave())
{
if (saveflag == true)
{
saveflag = false;
_context.BeginSaveChanges(onSaveComplete, TheOrderProductViewModel.SalesOrderDetails);
}
}
}
Hope it helps.