使用特定方法对添加到列表中的对象进行排序

本文关键字：对象 排序 列表 方法 添加 | 更新日期: 2024-09-25 10:51:31

我正在尝试对已添加到列表中的项目进行排序，该列表在添加列表项目后显示在列表框上。（我使用了继承-车辆类（基类）和汽车、卡车和摩托车是派生类）。

问题是，我收到了一种排序程序必须遵循的方法（或者我必须使用的方法），以对列表框中显示的添加项目进行排序。有人能解释一下我如何在主表格中的列表中实现这个方法吗？

我有以下代码：

主要形式：

namespace 3
{
public partial class Form1 : Form
{
    VehicleList _VList = new VehicleList();
    public Form1()
    {
        InitializeComponent();
    }
    //Add a vehicle to the list using inheritance
    private void button1_Click(object sender, EventArgs e)
    {
        if (comboBox1.SelectedIndex == 0)
        {
            Car myCar = new Car();
            myCar.VehicleRegistration = textBox1.Text;
            myCar.EngineNumber = textBox2.Text;
            myCar.Make = textBox3.Text;
            myCar.Model = textBox4.Text;
            myCar.EngineSize = Convert.ToInt32(textBox5.Text);
            myCar.Colour = textBox6.Text;
            //Add car to the list
            _VList.Add(myCar);
            //Display list
            listBox1.Items.Add(myCar.ToString());
            //Clear textboxes
            comboBox1.ResetText();
            textBox1.Clear();
            textBox2.Clear();
            textBox3.Clear();
            textBox4.Clear();
            textBox5.Clear();
            textBox6.Clear();
        }
        else if (comboBox1.SelectedIndex == 1)
        {
            Truck myTruck = new Truck();
            myTruck.VehicleRegistration = textBox1.Text;
            myTruck.EngineNumber = textBox2.Text;
            myTruck.Make = textBox3.Text;
            myTruck.Model = textBox4.Text;
            myTruck.EngineSize = Convert.ToInt32(textBox5.Text);
            myTruck.LoadCapacity = Convert.ToInt32(textBox6.Text);
            //Add truck to list
            _VList.Add(myTruck);
            //Display list
            listBox1.Items.Add(myTruck.ToString());
            //Clear textboxes
            comboBox1.ResetText();
            textBox1.Clear();
            textBox2.Clear();
            textBox3.Clear();
            textBox4.Clear();
            textBox5.Clear();
            textBox6.Clear();
        }
        else if (comboBox1.SelectedIndex == 2)
        {
            Motorbike myMotorbike = new Motorbike();
            myMotorbike.VehicleRegistration = textBox1.Text;
            myMotorbike.EngineNumber = textBox2.Text;
            myMotorbike.Make = textBox3.Text;
            myMotorbike.Model = textBox4.Text;
            myMotorbike.EngineSize = Convert.ToInt32(textBox5.Text);
            myMotorbike.TopSpeed = Convert.ToDouble(textBox6.Text);
            //Add motorbike to list
            _VList.Add(myMotorbike);
            //Display list
            listBox1.Items.Add(myMotorbike.ToString());
            //Clear textboxes
            comboBox1.ResetText();
            textBox1.Clear();
            textBox2.Clear();
            textBox3.Clear();
            textBox4.Clear();
            textBox5.Clear();
            textBox6.Clear();
        }
    }
    private void button2_Click(object sender, EventArgs e)
    {
        //Sort the items in the list when the sort button is pressed
        //HOW do I apply this method to my list?
        _VList.mySort();
    }
}
}

我必须使用的方法在VehicleList类中，如下所示：

class VehicleList : List<Vehicle>
{
    public void mySort()
    {
        this.Sort(delegate(Vehicle p1, Vehicle p2)
        {
            return p1.VehicleRegistration.CompareTo(p2.VehicleRegistration);
        });
    }
}

感谢

J

使用特定方法对添加到列表中的对象进行排序

假设您的mySort()方法已经完成（因为您说它是给您的），您应该将所有车辆添加到myVehicle中，而不是使用_VList。这将允许您调用myVehicle.mySort()。

使用Func委托对列表进行排序的演示：

public partial class Form1 : Form
{
    private VehicleList vehicleList = new VehicleList
    {
        new Vehicle{ VehicleRegistration = "b"},
        new Vehicle{ VehicleRegistration = "a"}
    };
    public Form1()
    {
        InitializeComponent();
        listBox1.DataSource = vehicleList;
    }
    private void btnSort_Click(object sender, EventArgs e)
    {
        vehicleList.SortBy(x => x.VehicleRegistration);
        UpdateListBox();
    }
    private void UpdateListBox()
    {
        listBox1.DataSource = null; //clear items
        listBox1.DataSource = vehicleList; //reset
    }
}
class VehicleList : List<Vehicle>
{
    public void SortBy(Func<Vehicle, IComparable> theThingToCompare)
    {            
        this.Sort(delegate(Vehicle v1, Vehicle v2) 
        {
            return theThingToCompare(v1).CompareTo(theThingToCompare(v2)); 
        });
    }
}
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