winform

Employee

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace WinApp03_ComboBox
 8 {
 9     enum EM_Department
10     {
11         开发部,
12         人事部,
13         财务部
14     }
15     class Employee
16     {
17         public int ID { get; set; }
18         public string Name { get; set; }
19         public EM_Department Department { get; set; }
20         public DateTime BirthDate { get; set; }
21 
22         /// <summary>
23         /// 重写ToString()方法 
24         /// </summary>
25         /// <returns>返回值: Name属性 </returns>
26         public override string ToString()
27         {
28             return this.Name;
29         }
30     }
31 }

From1

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Linq;
 7 using System.Text;
 8 using System.Threading.Tasks;
 9 using System.Windows.Forms;
10 
11 namespace WinApp03_ComboBox
12 {
13     public partial class Form1 : Form
14     {
15         public Form1()
16         {
17             InitializeComponent();
18         }
19 
20         private void Form1_Load(object sender, EventArgs e)
21         {
22             /**       
23             // 向comboBox1中添加字符串
24             comboBox1.Items.Add("Hello");
25             comboBox1.Items.Add("World");
26             comboBox1.Items.Add("你好,世界");
27             // 设置默认索引
28             comboBox1.SelectedIndex = 2;   
29              * */
30 
31             List<Employee> employees = new List<Employee>()
32             {
33                 new Employee(){ID = 1, Name = "张三", BirthDate = new DateTime(1988,04,23), Department = EM_Department.开发部},
34                 new Employee(){ID = 2, Name = "李四", BirthDate = new DateTime(1990,10,08), Department = EM_Department.财务部},
35                 new Employee(){ID = 3, Name = "王五", BirthDate = new DateTime(1995,03,06), Department = EM_Department.人事部},
36                 new Employee(){ID = 4, Name = "赵六", BirthDate = new DateTime(1990,07,09), Department = EM_Department.开发部}
37             };
38 
39             // 绑定数据源
40             comboBox1.DataSource = employees;
41             // 显示的是数据源的Name属性
42             comboBox1.DisplayMember = "Name";
43             // "值"字段是数据源的ID属性
44             comboBox1.ValueMember = "ID";
45             // 设置索引,默认不选择(-1)
46             comboBox1.SelectedIndex = -1;
47         }
48 
49         private void comboBox1_SelectedValueChanged(object sender, EventArgs e)
50         {
51             if ( -1 == comboBox1.SelectedIndex )
52             {
53                 label1.Text = "当前选中项索引: -1";
54                 label2.Text = "当前未选中任何项";
55                 label3.Text = "当前未选中任何项";
56             }
57             label1.Text = "当前选中项索引: " + comboBox1.SelectedIndex.ToString();
58             label2.Text = "当前选中项ID: " + comboBox1.SelectedValue.ToString();
59             label3.Text = "当前选中项Name: " + comboBox1.SelectedItem.ToString();
60         }
61 
62     }
63 }