用DropDownList把这个二级显示出来

一个有点假的方法，在数据库中读取出来的二级数据前面加写 就是加空格，让它靠后，这有点假了

cs文件 protected void Page_Load(object sender, EventArgs e)
        {
            this.test.InnerHtml = load().ToString();
        }        private StringBuilder load()
        {
            Category c1 = new Category(1, "一汽大众", 0);
            Category c2 = new Category(2, "上海大众", 0);
            Category c3 = new Category(3, "进口大众", 0);
            Category c11 = new Category(4, "cc", 1);
            Category c12 = new Category(5, "迈腾", 1);
            Category c13 = new Category(6, "速腾", 1);            Category c21 = new Category(7, "朗逸", 2);
            Category c22 = new Category(8, "POLO", 2);            Category c31 = new Category(9, "高尔夫", 3);
            Category c32 = new Category(9, "尚酷", 3);            List<Category> categories = new List<Category>();
            categories.Add(c1);
            categories.Add(c2);
            categories.Add(c3);
            categories.Add(c11);
            categories.Add(c12);
            categories.Add(c13);
            categories.Add(c21);
            categories.Add(c22);
            categories.Add(c31);
            categories.Add(c32);
            StringBuilder sbHtml = new StringBuilder();
            sbHtml.Append(@"<select name=""category"">");
            foreach (Category parent in GetParent(categories, 0))
            {
                sbHtml.AppendFormat(@"<option id=""{0}"">{1}</option>", parent.Id, parent.CategoryName);
                foreach (Category child in GetParent(categories, parent.Id))
                {
                    sbHtml.AppendFormat(@"<option id=""{0}"">     {1}</option>", child.Id, child.CategoryName);
                }
            }
            sbHtml.Append("</select>");
            return sbHtml;
        }        private List<Category> GetParent(List<Category> categories, int flag)
        {
            List<Category> getList = new List<Category>();
            foreach (Category category in categories)
            {
                if (category.FlagId == flag) getList.Add(category);
            }
            return getList;
        }
Category类 public class Category
    {
        public Category() { }
        public Category(int id, string category, int flagId)
        {
            this.Id = id;
            this.CategoryName = category;
            this.FlagId = flagId;
        }        private int _id;
        private string _categoryName;
        private int _flagId;
//没写属性
}界面<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>无标题页</title>
</head>
<body>
    <div id="test" runat="server">
    </div>
</body>
</html>
效果就是你上面的图片

sbHtml.Append(@"<select name=""category"">");
sbHtml.Append(@"<option>请选择系列</option>");

比如我把这个分类写入数据库了！！把这个分类在大众CC，我进去修改就要默认是大众CC!!
跟那SelectedValue一样！！

在后台处理数据
给手动的家空格转义然后给dropdownlist数据源

都很强大，我觉得要是能custom 能override就好，好吧赶个时间我试试

那个div是runat ="server"的。你默认分类那个可以从查询好的列表里检索。

其实楼主要的效果就是：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style type="text/css">
optgroup{
font-size:larger;
font-weight:bold;
}
</style>
</head><body>
<select>
<optgroup label="Swedish Cars">
<option value ="volvo">Volvo</option>
<option value ="saab">Saab</option>
</optgroup>

<optgroup label="German Cars">
<option value ="mercedes">Mercedes</option>
<option value ="audi">Audi</option>
</optgroup>
</select>
</body>
</html>
select被封装成dropdownlist，楼主可以找找对应的方法。。

当然，你不用dropdownlist也可以，直接拼接html就好了，主要看楼主习惯不！

如果是斜体字的话，样式改一下就好了。。
optgroup{
font-size:larger;
font-weight:bold;
font-style:italic;
}

dropdownlist递归
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;public partial class Default3 : System.Web.UI.Page
{

    public DataSet ds = null;
    public DataTable table = new DataTable();
    public SqlConnection con = null;
    public SqlDataAdapter ada = null;
    public string Kong = "";
    //public int i = 0;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            con = new SqlConnection("server=192.168.0.21;database=zgag_sysframe;uid=sa;pwd=sa;");
            ada = new SqlDataAdapter("select resid,resname,parentid from res", con);
            ds = new DataSet();
            ada.Fill(ds);
            table = ds.Tables[0];
            DataView view = new DataView();
            view.Table = table;
            foreach (DataRow row in view.Table.Select("parentid='root'"))
            {
                ListItem lt = new ListItem(row["resname"].ToString(), row["resid"].ToString());
                DropDownList1.Items.Add(lt);                Method_In(DropDownList1.Items[DropDownList1.Items.Count-1].Value);            }
        }
    }
    public void Method_In(string resid)
    {
        DataView view = new DataView();
        view.Table = table;
        DataRow[] rows = view.Table.Select("parentid='"+resid+"'");
        if (rows.Length > 0)
        {
            Kong = Kong + "－";
            foreach (DataRow row in rows)
            {
                ListItem lt = new ListItem(Kong + row["resname"].ToString(), row["resid"].ToString());
                DropDownList1.Items.Add(lt);
                Method_In(DropDownList1.Items[DropDownList1.Items.Count - 1].Value);
            }
            Kong = Kong.Remove(0, 1);
        }
    }
}

自已做写一个控件  <cc1:SmartDropDownList ID="SmartDropDownList1" runat="server">
    </cc1:SmartDropDownList>
pulic void ss(string car_Brand,string SmartDropDownList1  )

{SqlDataReader rd = DC.read("select Series_id,Series_name from Car_Series where series_Brand=" + car_Brand+ " ");
            while (rd.Read())
            {               ListItem li = new ListItem(rd[1].ToString(), "optgroup");
               SmartDropDownList1.Items.Add(li);                SqlDataReader rs = DC.read("select cars_id,cars_name  from Car_cars where cars_series=" + rd[0] + "");
               while (rs.Read())
                {
                   li = new ListItem(rs[1].ToString(), rs[0].ToString());
                   SmartDropDownList1.Items.Add(li);
               }
                rs.Close();
            }
            rd.Close();
}
红色那个控件要怎么定义呢？

调试易

用DropDownList把这个二级显示出来

解决方案 »