private void DeleteCustomersButton_OnClick(object sender, RoutedEventArgs e)
{
IList selectedCustomers = CustomersDataGrid.SelectedItems;
int customersSize = selectedCustomers.Count;
for (var i = 0; i < customersSize; i++)
{
DataRowView row = (DataRowView)CustomersDataGrid.SelectedItems[i];
string textId = row["Id"].ToString();
int id = Convert.ToInt32(textId);
_client.DeleteClient(id);
}
CustomersTabItem_OnLoaded(sender, e);
}