泛型的小例子,C#3.5版

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

namespace Comb
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void addSt()
        {
            List<ComboBoxItem<Student>> list = new List<ComboBoxItem<Student>>();
            list.Add(new ComboBoxItem<Student>("", null));
            Student s1 = new Student("张三", 15);
            Student s2 = new Student("李四", 20);
            list.Add(new ComboBoxItem<Student>(s1.Name, s1));
            list.Add(new ComboBoxItem<Student>(s2.Name, s2));
            //绑定下拉框
            comboBox1.DataSource = list;
            comboBox1.DisplayMember = "ItemText";
            comboBox1.ValueMember = "ItemValue";
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            //addSt();
            if (comboBox1.SelectedIndex > 0)
            {
                Student s = (Student)comboBox1.SelectedValue;
                MessageBox.Show(s.Age.ToString());
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            addSt();
        }

    }

    public class ComboBoxItem<T>
    {
        //ItemText显示的文字
       // private string _itemText;
        public string ItemText
        {
            get;set;
            //get { return _itemText ; }
            //set { _itemText = value; }
        }
        //ItemValue实际的值
       // private T _itemValue;
        public T ItemValue
        {
            get;set;
            //get { return _itemValue; }
            //set { _itemValue = value; }
        }
        //构造方法
        public ComboBoxItem(string itemText, T itemValue)
        {
            //this._itemText = itemText;
            //this._itemValue = itemValue;
            ItemText = itemText;
            ItemValue = itemValue;
        }
        //自定义方法
        //确定指定的对象是否等于当前对象
        public override bool Equals(object obj)
        {
           // 2643993
            if (obj is ComboBoxItem<T>)
            {
                ComboBoxItem<T> rhs = (ComboBoxItem<T>)obj;
               // if (_itemText.Equals(rhs.ItemText) && _itemValue.Equals(rhs.ItemValue))
                if(ItemText.Equals(rhs.ItemText)&&ItemValue.Equals(rhs.ItemValue))
                    return true;
                else
                    return false;
            }
            else
                return false;
        }
        //获取当前对象的哈希代码
        public override int GetHashCode()
        {
            return ItemText.GetHashCode() + ItemValue.GetHashCode();
        }
        //重载相等操作符
        public static bool operator ==(ComboBoxItem<T> lhs, ComboBoxItem<T> rhs)
        { return lhs.Equals(rhs); }
        //重载不等
        public static bool operator !=(ComboBoxItem<T> lhs, ComboBoxItem<T> rhs)
        { return !(lhs.Equals(rhs)); }
    }
    //学生对象
    public class Student
    {
        //姓名
        private string _name;
        public string Name
        { get { return _name; } }
        //年龄
        private int _age;
        public int Age
        { get { return _age; } }
        //构造方法
        public Student(string name, int age)
        {
            _name = name;
            _age = age;
        }
    }
}