winform

Employee

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

namespace WinApp03_ComboBox
{
    enum EM_Department
    {
        开发部,
        人事部,
        财务部
    }
    class Employee
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public EM_Department Department { get; set; }
        public DateTime BirthDate { get; set; }

        /// <summary>
        /// 重写ToString()方法 
        /// </summary>
        /// <returns>返回值: Name属性 </returns>
        public override string ToString()
        {
            return this.Name;
        }
    }
}

From1

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 WinApp03_ComboBox
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            /**       
            // 向comboBox1中添加字符串
            comboBox1.Items.Add("Hello");
            comboBox1.Items.Add("World");
            comboBox1.Items.Add("你好,世界");
            // 设置默认索引
            comboBox1.SelectedIndex = 2;   
             * */

            List<Employee> employees = new List<Employee>()
            {
                new Employee(){ID = 1, Name = "张三", BirthDate = new DateTime(1988,04,23), Department = EM_Department.开发部},
                new Employee(){ID = 2, Name = "李四", BirthDate = new DateTime(1990,10,08), Department = EM_Department.财务部},
                new Employee(){ID = 3, Name = "王五", BirthDate = new DateTime(1995,03,06), Department = EM_Department.人事部},
                new Employee(){ID = 4, Name = "赵六", BirthDate = new DateTime(1990,07,09), Department = EM_Department.开发部}
            };

            // 绑定数据源
            comboBox1.DataSource = employees;
            // 显示的是数据源的Name属性
            comboBox1.DisplayMember = "Name";
            // "值"字段是数据源的ID属性
            comboBox1.ValueMember = "ID";
            // 设置索引,默认不选择(-1)
            comboBox1.SelectedIndex = -1;
        }

        private void comboBox1_SelectedValueChanged(object sender, EventArgs e)
        {
            if ( -1 == comboBox1.SelectedIndex )
            {
                label1.Text = "当前选中项索引: -1";
                label2.Text = "当前未选中任何项";
                label3.Text = "当前未选中任何项";
            }
            label1.Text = "当前选中项索引: " + comboBox1.SelectedIndex.ToString();
            label2.Text = "当前选中项ID: " + comboBox1.SelectedValue.ToString();
            label3.Text = "当前选中项Name: " + comboBox1.SelectedItem.ToString();
        }

    }
}