列出二级，三级分类

[xiaomangxian]

我有一个数据库的表a表,结构如下

aid atitle apid (其中aid是主键，自动)
1 dsaffd 0
2 fdsaf 1
3 fdsaf 1
4 fdkaklk 3

上面表明，apid是0的，表示是一级分类，1表示，这个信息是aid为1的分类下面的分类，以此类推，最多有三级分类，我现在想通过

树形结构把这个分类读出来，请问该怎么写呢？
结构形式是

一级分类A
二级分类A
三级分类A
三级分类B
二级分类B
一级分类B
二级分类A
二级分类B
三级分类A
三级分类B

请问该怎么做呢？是否有这样的控件呢？谢谢

[wuyq11]

http://www.cnblogs.com/jarod99/archive/2008/12/26/1363183.html

[memorywang]

最好写成无限级的.我是用Hashtable实现的.MenuId,MenuParent分别对应你的aid,apid.我把代码贴给你.实现了要结贴给分啊!

        Hashtable myHT_index = new Hashtable();
        Hashtable myHT_data = new Hashtable();

        String write_tree = "";

        protected void NavBar_DataBind()
        {
            SqlConnection objConn = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"]);
            string parentString;
            parentString = "select MenuId,MenuName,MenuParent,MenuDepth,MenuLink from sys_ManageMenu where Visible<>0 order by MenuParent asc,MenuOrder";
            SqlDataAdapter daParent = new SqlDataAdapter(parentString, objConn);
            DataSet dsParent = new DataSet();
            objConn.Open();
            daParent.FillSchema(dsParent, SchemaType.Source, "parentTable");
            daParent.Fill(dsParent, "parentTable");
            objConn.Close();

            for (int i = 0; i < dsParent.Tables[0].Rows.Count; i++)
            {
                if (myHT_index.Contains(dsParent.Tables[0].Rows[i]["MenuParent"].ToString()))
                {
                    myHT_index[dsParent.Tables[0].Rows[i]["MenuParent"].ToString()] += "," + dsParent.Tables[0].Rows[i]["MenuId"].ToString();
                }
                else
                {
                    myHT_index.Add(dsParent.Tables[0].Rows[i]["MenuParent"].ToString(), dsParent.Tables[0].Rows[i]["MenuId"].ToString());
                }

                if (!myHT_data.Contains(dsParent.Tables[0].Rows[i]["MenuId"].ToString()))
                {
                    myHT_data.Add(dsParent.Tables[0].Rows[i]["MenuId"].ToString(), new string[] { dsParent.Tables[0].Rows[i]["MenuId"].ToString(), dsParent.Tables[0].Rows[i]["MenuName"].ToString(), dsParent.Tables[0].Rows[i]["MenuParent"].ToString(), dsParent.Tables[0].Rows[i]["MenuLink"].ToString() });
                }
            }
            write_tree+="<table>";
            show_NavMenu("0", 0);
            write_tree+="</table>";
            leftNavMenu.Text = write_tree;//leftNavMenu是一个Label
        }

        protected void show_NavMenu(string MenuParent,int depth)
        {
            if (myHT_index.Contains(MenuParent))
            {
                String[] MenuId_item = myHT_index[MenuParent].ToString().Split(',');
                for (int i = 0; i < MenuId_item.Length; i++)
                {
                    if (myHT_data.Contains(MenuId_item[i].ToString()))
                    {
                        write_tree += "<tr onmouseover=currentcolor=this.style.backgroundColor;this.style.backgroundColor='#C1E1F1' onmouseout=this.style.backgroundColor=currentcolor>";
                        write_tree += "<td><span style='color:#006666;'>";
                        for (int j = 0; j < depth; j++)
                        {
                            write_tree += "┃";
                        }
                        write_tree += "┣ ";
                        String[] Menu = (String[])myHT_data[MenuId_item[i].ToString()];
                        if (MenuParent == "0")
                        {
                            write_tree += "<span style='font-size:13px;font-weight:bold; cursor:hand;'>" + Menu[1].ToString() + "</span>";
                        }
                        else
                        {
                            if (Menu[3].IndexOf("?") > 0)
                            {
                                
                                write_tree += "<a href='" + Menu[3].ToString() + "&MNid=" + Menu[0].ToString() + "' target='rightFrame'><span style='color:#008787;font-size:11px;'>" + Menu[1].ToString() + "</span></a>";
                            }
                            else
                            {
                                write_tree += "<a href='" + Menu[3].ToString() + "?MNid=" + Menu[0].ToString() + "' target='rightFrame'><span style='color:#008787;font-size:11px;'>" + Menu[1].ToString() + "</span></a>";
                            }
                        }
                        write_tree += "</span></td>";
                        write_tree += "</tr>";

                        if (myHT_index.Contains(MenuId_item[i].ToString()))
                        {
                            show_NavMenu(MenuId_item[i].ToString(), depth + 1);
                        }
                    }

                }
            }
        }

[scy251147]

那得用到递归，先帮顶，吃饭后回来写

[hernmmy]

帮顶