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：

 string sqlcon = "Data Source=.;Initial Catalog=Test;User ID=sa;Password=******";

        public List<ModelClass> FindAll()
        {
            try
            {
                List<ModelClass> modList = new List<ModelClass>();
                using (SqlConnection con = new SqlConnection(sqlcon))
                {
                    con.Open();
                    string sql = "select ID,Name,Address from TEST1";
                    SqlCommand com = new SqlCommand();
                    com.CommandText = sql;
                    com.CommandType = CommandType.Text;
                    com.Connection = con;
                    using (SqlDataReader read = com.ExecuteReader())
                    {
                        while (read.Read())
                        {
                            modList.Add(new ModelClass() { ID = Convert.ToInt32(read["ID"].ToString()), Name = read["Name"].ToString(), Address = read["Address"].ToString() });
                        }
                    }
                    return modList;
                }
            }
            catch (Exception)
            {
                throw;
            }
        }

        public System.Data.DataSet FindAllToDS()
        {
            try
            {
                using (SqlConnection con = new SqlConnection(sqlcon))
                {
                    con.Open();
                    System.Data.DataSet ds = new DataSet();
                    string sql = "select ID,Name,Address from TEST1";
                    SqlDataAdapter sda = new SqlDataAdapter();
                    sda.SelectCommand = new SqlCommand(sql,con);
                    sda.Fill(ds);
                    return ds;
                }
            }
            catch (Exception)
            {

                throw;
            }
        }

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:

public class gzClass
    {
        public int ID { get; set; }
        public string NameAndAddress { get; set; }
    }

第一种实现方法：在后台试用构造类去绑定数据

 protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                //元数据
                List<ModelClass> modelList = new List<ModelClass>();
                System.Data.DataTable dt = new System.Data.DataTable();
                //赋值护具
                List<gzClass> strListToList = new List<gzClass>();
                List<gzClass> dtList = new List<gzClass>();
                //测试连接数据库类
                Class1 c1 = new Class1();
                //赋值
                modelList = c1.FindAll();
                dt = c1.FindAllToDS().Tables[0];
                //遍历取值并给与另一个构造类
                foreach (ModelClass item in modelList)
                {
                    strListToList.Add(new gzClass() { ID = item.ID, NameAndAddress = item.Name + "(" + item.Address + ")" });
                }


                if (dt != null && dt.Rows.Count > 0)
                {
                    foreach (System.Data.DataRow dsItem in dt.Rows)
                    {
                        dtList.Add(new gzClass() { ID = Convert.ToInt32(dsItem["ID"]), NameAndAddress = dsItem["Name"] + "(" + dsItem["Address"] + ")" });
                    }
                }

                

                this.ddl_list.DataSource = strListToList;
                this.ddl_list.DataTextField = "NameAndAddress";
                this.ddl_list.DataValueField = "ID";
                this.ddl_list.DataBind();

                this.ddl_ds.DataSource = dtList;
                this.ddl_ds.DataTextField = "NameAndAddress";
                this.ddl_ds.DataValueField = "ID";
                this.ddl_ds.DataBind();

            }
        }

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

 public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";

            //元数据
            List<ModelClass> modelList = new List<ModelClass>();
            System.Data.DataTable dt = new System.Data.DataTable();
            StringBuilder sbu1 = new StringBuilder();
            //测试连接数据库类
            Class1 c1 = new Class1();
            //赋值
            modelList = c1.FindAll();
            dt = c1.FindAllToDS().Tables[0];

            //拼接数据
            sbu1.AppendLine("<select name="ddl_list" id="ddl_list">");
            foreach (ModelClass modelItem in modelList)
            {
                sbu1.AppendLine("<option value=""+modelItem.ID+"">"+modelItem.Name+"("+modelItem.Address+")</option>");
            }
            sbu1.AppendLine("</select>");


            sbu1.AppendLine(" <select name="ddl_datarow" id="ddl_datarow">");
            foreach (System.Data.DataRow drItem in dt.Rows)
            {
                sbu1.AppendLine("<option value=""+drItem["ID"].ToString()+"">"+drItem["Name"]+"("+drItem["Address"]+")</option>");
            }
            sbu1.AppendLine("</select>");
            context.Response.Write(sbu1.ToString());
            context.Response.End();
        }

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。