下面是我凭感觉加的程序，有没有问题，哪里可以改进？

1. 在MainWindow.xaml.cs程序下，添加 RemoveAppointment方法
   public void RemoveAppointment()
   {
   if (SelectedAppointment.Id == 0) { return; }
   else
   {
   using (var db = new AppDbContext())
   {
   var appointmentToRemove = db.Appointments
   .Where(a => a.Id == SelectedAppointment.Id)
   .FirstOrDefault();
   db.Appointments.Remove(appointmentToRemove);
   db.SaveChanges();
   }
   LoadAppointments(SelectedCustomer.Id);
   }
   }
2. 在MainWindow.xaml.cs程序下添加RemoveAppointment_Click事件 和
   private void RemoveAppointment_Click(object sender, RoutedEventArgs e)
   {
   try
   {
   using (var db = new AppDbContext())
   {
   var selectedAppointment = (AppointmentViewModel)AppointmentList.SelectedValue;
   if (selectedAppointment!=null)
   {
   _viewModel.RemoveAppointment();
   }
   }
   }
   catch (Exception error)
   {
   MessageBox.Show(error.ToString());
   }
   }
   3.在MainViewModel.cs下添加 SelectedAppointment的构造方法和_selectedAppointment的私有字段
   public AppointmentViewModel SelectedAppointment
   {
   get => _selectedAppointment; set
   {
   if (_selectedAppointment != value)
   {
   _selectedAppointment = value;
   RisePropertyChanged(nameof(SelectedAppointment));
   }
   }
   }
   4.在MainViewModel下添加SelectedAppointment视图模型
   public AppointmentViewModel SelectedAppointment
   { get => _selectedAppointment; set
   {
   if (_selectedAppointment != value)
   { _selectedAppointment = value;
   RisePropertyChanged(nameof(SelectedAppointment));}
   }
   }
   5.在 xaml的预约列表的Listview下修改为：< listview Name=“AppointmentList” ItemsSource="{Binding Appointments, Mode=TwoWay}" SelectedItem="{Binding SelectedAppointment, Mode=TwoWay}" DisplayMemberPath=“Time” Height=“270”/>