ASP.NET

代码：
 1         //声明泛型
 2         List<category> inof = new List<category>();//二级分类
 3 
 4         //声明类使用的对象类
 5         public class category
 6         {
 7             public category(string id, string name)
 8             {
 9                 Id = id;
10                 Name = name;
11             }
12 
13             private string id;
14 
15             public string Id
16             {
17                 get { return id; }
18                 set { id = value; }
19             }
20 
21             private string name;
22 
23             public string Name
24             {
25                 get { return name; }
26                 set { name = value; }
27             }
28         }
29 
30         //获取信息
31         public void selectdatabind()
32         {
33             SqlDataReader sdr = SQLHelper.ExcuteReader("select ID, CategoryName from Tb_APCategory where ParentID = 1000", CommandType.Text);
34             while (sdr.Read())
35             {
36                 SqlDataReader sdr_2 = SQLHelper.ExcuteReader("select ID, CategoryName from Tb_APCategory where ParentID = " + sdr["ID"].ToString() + "", CommandType.Text);
37                 while (sdr_2.Read())
38                 {
39                     inof.Add(new category(sdr_2["ID"].ToString(), sdr_2["CategoryName"].ToString()));
40                 }
41             }
42         }
43 
44 
45         //使用
46         this.DropDownList2.DataSource = inof;
47         this.DropDownList2.DataValueField = "ID";
48         this.DropDownList2.DataTextField = "Name";
49         this.DropDownList2.DataBind();