Question

我已经用C＃编写了这个程序，用于我今晚要完成的任务。我要做的是创建一个名为“Employee”的类，将信息显示在List Box上。我相信我把所有东西放在一起，而且我没有显示任何语法错误，但是当我尝试运行程序时，没有任何反应。你认为你可以帮我找出它不工作的原因吗？出现的只是一个空白列表框。这是我在Form1.cs上的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Adam_Zeidan___IS_204___HW10CH9_4
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            listBox1.Items.Add("Name\t\tID Number\tDepartment\tPosition");

            Employee emp1 = emp1 = new Employee();
            emp1.Name = "Susan Meyers";
            emp1.IdNumber = 47899;
            emp1.Department = "Accounting";
            emp1.Position = "Vice President";
            listBox1.Items.Add(emp1.Name + "\t" + emp1.IdNumber + "\t\t" +     emp1.Department + "\t" + emp1.Position);

            Employee emp2 = emp2 = new Employee();
            emp2.Name = "Mark Jones";
            emp2.IdNumber = 39119;
            emp2.Department = "IT";
            emp2.Position = "Programmer";
            listBox1.Items.Add(emp2.Name + "\t" + emp2.IdNumber + "\t\t" +     emp2.Department + "\t" + emp2.Position);

            Employee emp3 = emp3 = new Employee();
            emp3.Name = "Joy Rogers";
            emp3.IdNumber = 81774;
            emp3.Department = "Manufacturing";
            emp3.Position = "Engineer";
            listBox1.Items.Add(emp3.Name + "\t" + emp3.IdNumber + "\t\t" +     emp3.Department + "\t" + emp3.Position);

        }

        private void listBox1_SelectedIndexChanged(object sender, EventArgs     e)
        {

        }
    }
}

现在这是我用来创建类的Employee.cs代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Adam_Zeidan___IS_204___HW10CH9_4
{
    class Employee
    {
        private string _name;
        private int _idNumber;
        private string _department;
        private string _position;

        public Employee()
        {
            _name = "";
            _idNumber = 0;
            _department = "";
            _position = "";
        }

        public Employee(string name, int idNumber)
        {
            _name = name;
            _idNumber = idNumber;
            _department = "";
            _position = "";
        }

        public Employee(string name, int idNumber, string department, string     position)
        {
            _name = name;
            _idNumber = idNumber;
            _department = department;
            _position = position;
        }

        public string Name
        {
            get
            {
                return _name;
            }
            set
            {
                _name = value;
            }
        }

        public int IdNumber
        {
            get
            {
                return _idNumber;
            }
            set
            {
                _idNumber = value;
            }
        }

        public string Department
        {
            get
            {
                return _department;
            }
            set
            {
                _department = value;
            }
        }

    public string Position
    {
        get
        {
            return _position;
        }
        set
        {
            _position = value;
        }
    }
}

你认为你可以帮我找出它无效的原因吗？

Answer 1

更改以下行

 Employee emp1 = new Employee();
 Employee emp2 = new Employee();
 Employee emp3 = new Employee();

到

xts:::current.xts_chob()

Answer 2

我尝试了给定的片段;这对我来说很合适，请检查ListBox的属性以获取它的可见性，并确保Form1_Load事件正在触发。我建议按以下方式在类中按overriding .ToString()简化代码：

public override string ToString()
    {
        return this.Name + "\t" + this.IdNumber + "\t\t" + this.Department + "\t" + this.Position;
    }

以便Form1_Load中的代码如下所示：

  Employee emp1 = new Employee();
  emp1.Name = "Susan Meyers";
  emp1.IdNumber = 47899;
  emp1.Department = "Accounting";
  emp1.Position = "Vice President";
  listBox1.Items.Add(emp1.ToString());
  Employee emp2 = new Employee();
  //init emp2 here
  listBox1.Items.Add(emp2.ToString());
  Employee emp3 = emp3 = new Employee();
  //init emp3 here
  listBox1.Items.Add(emp3.ToString());

在C＃中创建Employee类时出错

2 个答案: