我错过了一个 if 语句吗？

Question

提前感谢您的帮助！

一些背景知识基本上我正在构建一个存储车辆（汽车、卡车、公共汽车）的应用程序，我有一个车辆超类，所有单独的类（car.cs、truck.cs、minibus.cs）都继承自这个超级类。

我还有一个名为“fleet”的类，我想将车辆添加到其中，然后在列表框中显示结果。

我的其他一切都在工作，但我无法像汽车那样让卡车和小巴更新并显示在列表框上。

这是我的车队课程，其中包括 car.cs；它工作正常，从汽车表单中获取的数据被添加并显示在列表框中。

class Fleet
{
    private List<Vehicle> theFleet = new List<Vehicle>(); 

    public List<Vehicle> fleet 
    {
        get
        {
            return theFleet;
        }
    }

    public void deleteFromFleet(Vehicle aCar)
    {
        theFleet.Remove(aCar);
    }

    public void addToFleet(Vehicle aCar)
    {
        theFleet.Add(aCar);
    }
}

这是我的主要表单，上面有列表框：

public partial class FrmHireCo : Form
{
    private Fleet myFleet = new Fleet();
    private ClientList mycustomer = new ClientList();

    //Fleet object used to store cars

    public FrmHireCo()
    {
        //Default constructor
        InitializeComponent();                
    }        

    private void updateFleetList()
    {   
        lstFleet.Items.Clear();
        foreach (Car c in myFleet.fleet)
        {
            string line = "Car: " + c.make+" " + c.colour;
            lstFleet.Items.Add(line);
        }
    }

    private void updateClientList()
    {   
        customers.Items.Clear();
        foreach (Customer c in mycustomer.clientlist)
        {
            string line = "Customer: " + c.name + " " + c.address;
            customers.Items.Add(line);
        }
    }

    private void btnAddCar_Click(object sender, EventArgs e)
    {
        //Add a new car
        FrmCar carGui = new FrmCar(); //Form used to add new car
        carGui.ShowDialog();
        Car myCar = carGui.car;         //Get new car from form
        myFleet.addToFleet(myCar);      //Add to fleet list
        updateFleetList();              //Uodate fleet list
    }

    private void lstFleet_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (lstFleet.SelectedIndex > -1)
        {
            int index = lstFleet.SelectedIndex;
            Car myCar = myFleet.fleet.ElementAt(index);
            FrmCar carGui = new FrmCar();
            carGui.car = myCar;
            carGui.Show();
        }
    }

    private void btnCustomer_Click(object sender, EventArgs e)
    {
        FrmCustomer customerGui = new FrmCustomer();
        customerGui.ShowDialog();
        Customer mycustomer = customerGui.customer;         
        mycustomer.addToClientList(mycustomer);      
        updateFleetList();
    }

    private void customers_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (customers.SelectedIndex > -1)
        {
            int index = customers.SelectedIndex;
            Customer myCustomer = mycustomer.clientlist.ElementAt(index);
            FrmCustomer customerGui = new FrmCustomer();
            customerGui.customer = myCustomer;
            customerGui.Show();
        }
    }
}

为任何帮助干杯！

Answer 1

private void updateFleetList()
    {   
        lstFleet.Items.Clear();
        foreach (Vehicle c in myFleet.fleet)
        {
            string line = "Car: " + c.make+" " + c.colour;
            lstFleet.Items.Add(line);
        }
    }

Answer 2

您应该包括所有车辆。

private void updateFleetList()
{   
    lstFleet.Items.Clear();
    foreach (Vehicle v in myFleet.fleet)
    {
        lstFleet.Items.Add(v);  
    }
}

另外，只需在所有 Vehicle 子类中覆盖 ToString，ListBox 就会固有地使用它；这样，并不是每个Vehicle 都需要Make 或Color 属性。