private void OnExitButtonCommand(object arguemnt)
 {
     if (confirm == null)
     {
         confirm = new ConfirmExitWindow();
     }
     if (confirm.ShowDialog() == true)
     {
         linkedVisit.ExitDate = DateTime.Now;
         var vm = (ConfirmExitViewModel)(confirm.DataContext);
         if (vm.Remark != null)
         {
             linkedVisit.Remark = vm.Remark;
         }
         SaveChangesCommand?.Invoke(this);
     }
     else
     {
     }
     confirm = null;
 }
 public ConfirmExitViewModel(ConfirmExitWindow view)
 {
     this.view            = view;
     ConfirmButtonCommand = new RelayCommand(OnConfirmButtonCommand);
     CancelButtonCommand  = new RelayCommand(OnCancelButtonCommand);
 }