在下拉列表中显示多个字段的两种方法

首先，我们需要从数据库中取到我们的数据

Class1：

 1  string sqlcon = "Data Source=.;Initial Catalog=Test;User ID=sa;Password=******";
 2
 3         public List<ModelClass> FindAll()
 4         {
 5             try
 6             {
 7                 List<ModelClass> modList = new List<ModelClass>();
 8                 using (SqlConnection con = new SqlConnection(sqlcon))
 9                 {
10                     con.Open();
11                     string sql = "select ID,Name,Address from TEST1";
12                     SqlCommand com = new SqlCommand();
13                     com.CommandText = sql;
14                     com.CommandType = CommandType.Text;
15                     com.Connection = con;
16                     using (SqlDataReader read = com.ExecuteReader())
17                     {
18                         while (read.Read())
19                         {
20                             modList.Add(new ModelClass() { ID = Convert.ToInt32(read["ID"].ToString()), Name = read["Name"].ToString(), Address = read["Address"].ToString() });
21                         }
22                     }
23                     return modList;
24                 }
25             }
26             catch (Exception)
27             {
28                 throw;
29             }
30         }
31
32         public System.Data.DataSet FindAllToDS()
33         {
34             try
35             {
36                 using (SqlConnection con = new SqlConnection(sqlcon))
37                 {
38                     con.Open();
39                     System.Data.DataSet ds = new DataSet();
40                     string sql = "select ID,Name,Address from TEST1";
41                     SqlDataAdapter sda = new SqlDataAdapter();
42                     sda.SelectCommand = new SqlCommand(sql,con);
43                     sda.Fill(ds);
44                     return ds;
45                 }
46             }
47             catch (Exception)
48             {
49
50                 throw;
51             }
52         }

我分别用list和DataSet两种方式取得了数据，首先我们需要构造一个实现这样方法的类

gzClass:

1 public class gzClass
2     {
3         public int ID { get; set; }
4         public string NameAndAddress { get; set; }
5     }

第一种实现方法：在后台试用构造类去绑定数据

 1  protected void Page_Load(object sender, EventArgs e)
 2         {
 3             if (!IsPostBack)
 4             {
 5                 //元数据
 6                 List<ModelClass> modelList = new List<ModelClass>();
 7                 System.Data.DataTable dt = new System.Data.DataTable();
 8                 //赋值护具
 9                 List<gzClass> strListToList = new List<gzClass>();
10                 List<gzClass> dtList = new List<gzClass>();
11                 //测试连接数据库类
12                 Class1 c1 = new Class1();
13                 //赋值
14                 modelList = c1.FindAll();
15                 dt = c1.FindAllToDS().Tables[0];
16                 //遍历取值并给与另一个构造类
17                 foreach (ModelClass item in modelList)
18                 {
19                     strListToList.Add(new gzClass() { ID = item.ID, NameAndAddress = item.Name + "(" + item.Address + ")" });
20                 }
21
22
23                 if (dt != null && dt.Rows.Count > 0)
24                 {
25                     foreach (System.Data.DataRow dsItem in dt.Rows)
26                     {
27                         dtList.Add(new gzClass() { ID = Convert.ToInt32(dsItem["ID"]), NameAndAddress = dsItem["Name"] + "(" + dsItem["Address"] + ")" });
28                     }
29                 }
30
31
32
33                 this.ddl_list.DataSource = strListToList;
34                 this.ddl_list.DataTextField = "NameAndAddress";
35                 this.ddl_list.DataValueField = "ID";
36                 this.ddl_list.DataBind();
37
38                 this.ddl_ds.DataSource = dtList;
39                 this.ddl_ds.DataTextField = "NameAndAddress";
40                 this.ddl_ds.DataValueField = "ID";
41                 this.ddl_ds.DataBind();
42
43             }
44         }

第二种方法：使用ajax异步加载，进行拼接，这时就要借助我们的一般处理程序了

 1  public void ProcessRequest(HttpContext context)
 2         {
 3             context.Response.ContentType = "text/plain";
 4
 5             //元数据
 6             List<ModelClass> modelList = new List<ModelClass>();
 7             System.Data.DataTable dt = new System.Data.DataTable();
 8             StringBuilder sbu1 = new StringBuilder();
 9             //测试连接数据库类
10             Class1 c1 = new Class1();
11             //赋值
12             modelList = c1.FindAll();
13             dt = c1.FindAllToDS().Tables[0];
14
15             //拼接数据
16             sbu1.AppendLine("<select name=\"ddl_list\" id=\"ddl_list\">");
17             foreach (ModelClass modelItem in modelList)
18             {
19                 sbu1.AppendLine("<option value=\""+modelItem.ID+"\">"+modelItem.Name+"("+modelItem.Address+")</option>");
20             }
21             sbu1.AppendLine("</select>");
22
23
24             sbu1.AppendLine(" <select name=\"ddl_datarow\" id=\"ddl_datarow\">");
25             foreach (System.Data.DataRow drItem in dt.Rows)
26             {
27                 sbu1.AppendLine("<option value=\""+drItem["ID"].ToString()+"\">"+drItem["Name"]+"("+drItem["Address"]+")</option>");
28             }
29             sbu1.AppendLine("</select>");
30             context.Response.Write(sbu1.ToString());
31             context.Response.End();
32         }

把数据返回并在页面中给值，下面是我的aspx页面

 1 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebTest1.WebForm1" %>
 2
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 4
 5 <html xmlns="http://www.w3.org/1999/xhtml">
 6 <head runat="server">
 7     <title></title>
 8 <script src="jquery-2.1.1.min.js" type="text/javascript"></script>
 9 </head>
10 <body>
11     <form id="form1" runat="server">
12     <div>
13         <asp:DropDownList ID="ddl_list" runat="server">
14         </asp:DropDownList>
15         <asp:DropDownList ID="ddl_ds" runat="server">
16         </asp:DropDownList>
17         <div id="ddlDisplay"></div>
18     </div>
19     </form>
20 </body>
21 </html>
22 <script type="text/javascript">
23     window.onload = function () {
24         $.ajax({
25             url: "ddlTest1.ashx",
26             type: "post",
27             async: false,
28             success: function (data) {
29                 if (data != "") {
30                     $("#ddlDisplay").html(data);
31                 }
32             }
33         });
34
35     }
36 </script>

本人想了半天只想出了这两种方法，欢迎补充，多多学习。