private void BtnCalcTotal_Click(object sender, RoutedEventArgs e) { vm.CalculateTotalCharge(); //open DetailWindow if (dw == null) { dw = new DetailWindow(vm) { Owner = this, WindowStartupLocation = WindowStartupLocation.CenterOwner }; dw.Closed += DW_Closed; dw.Show(); } }
private void DW_Closed(object sender, System.EventArgs e) => dw = null;