[分享]分享一个自己写的理论上支持无限级分类的树型机构

NqIceCoffee 2007-10-11 10:06:49

.aspx页面

<html xmlns="http://www.w3.org/1999/xhtml" >

<head>

    <title>myTree</title>

    <style type="text/css">

    <!--

        ul{margin:0px;padding:4px 0px 4px 25px;list-style:none;}

        li,span,div{font-size:12px;}

    //-->

    </style>

</head>

<body>

<asp:Literal ID="lit_Tree" runat="server"></asp:Literal>

<script language="javascript" type="text/javascript">

<!--

    function Change(id) {

        var el = document.getElementById(id);

        if(el.style.display == "none") {

            el.style.display = "";

            document.getElementById("img_" + id).innerHTML = "-";

        } else {

            el.style.display = "none";

            document.getElementById("img_" + id).innerHTML = "+";

        }

    }

//-->

</script>

</body>

</html>

.cs

public partial class index : System.Web.UI.Page

    {

        private DBHelper db = new DBHelper();



        protected void Page_Load(object sender, EventArgs e)

        {

            StringBuilder sb_tree = new StringBuilder();

            if (Cache["Tree"] == null)

                CacheTree();

            GetTree(0, sb_tree);

            lit_Tree.Text = sb_tree.ToString();

        }

        protected void GetTree(int parentID, StringBuilder sb_tree)

        {

            DataTable dt_all = Cache["Tree"] as DataTable;

            string typeName = GetTypeName(parentID); 

            sb_tree.Append(string.Format("<span onClick=\"Change('{0}');\" style=\"cursor:pointer;\"><span id='img_{0}'>+</span> {1}</span>", parentID, typeName));

            DataRow[] dr_Item = dt_all.Select(string.Format("typeParentID={0}", parentID));

            if (parentID == 0)

                sb_tree.Append(string.Format("<div id='{0}' style='display:;'>\r\n", parentID));

            else

                sb_tree.Append(string.Format("<div id='{0}' style='display:none;'>\r\n", parentID));

            foreach(DataRow dr in dr_Item)

            {

                sb_tree.Append("<ul>\r\n");

                if (HaveChild(int.Parse(dr["typeID"].ToString())))

                    GetTree(int.Parse(dr["typeID"].ToString()), sb_tree); //===>重要!递归!

                else

                    sb_tree.Append(string.Format("<li>·{0}</li>\r\n", dr["typeName"].ToString()));

                sb_tree.Append("</ul>\r\n");

            }

            sb_tree.Append("</div>\r\n");

        }



        //判断该节点是否有子节点

        protected bool HaveChild(int myID)

        {

            DataTable dt_all = Cache["Tree"] as DataTable;

            return dt_all.Select(string.Format("typeParentID={0}", myID)).Length > 0;

        }



        //缓存该树的所有节点

        protected void CacheTree()

        {

            string cmdText = "select * from type_trade";

            DataTable dt = db.ExecuteDataTable(cmdText);

            Cache.Insert("Tree", dt);

            dt = null;

        }



        //根据节点取该节点的名称

        protected string GetTypeName(int typeID)

        {

            if (typeID == 0)

                return "根节点";

            if (Cache["Tree"] == null)

                CacheTree();

            DataTable dt_all = Cache["Tree"] as DataTable;

            return dt_all.Select(string.Format("typeID={0}", typeID))[0]["typeName"].ToString();

        }

    }