TreeView控件无限级 一次性加载和异步加载剖析

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="MSTreeView.aspx.cs" Inherits="MSTreeView" %>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>TreeView一次性加载和异步加载</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ScriptManager ID="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                <table>
                    <tr>
                        <td style="width:200px; height:600px; vertical-align:top;">
                            一次性加载<br />
                            <asp:TreeView ID="TreeView2" runat="server" ShowLines="true">
                            </asp:TreeView>
                        </td>
                        <td style="width:200px; height:600px; vertical-align:top;">
                            异步加载<br />
                            <asp:TreeView ID="TreeView1" runat="server"  ShowLines="true"
                                OnTreeNodePopulate="TreeView1_TreeNodePopulate" EnableClientScript="true" ExpandDepth="0">
                            </asp:TreeView>
                        </td>
                    </tr>
                </table>
            </ContentTemplate>
        </asp:UpdatePanel>
    </div>
    </form>
</body>
</html>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class MSTreeView : System.Web.UI.Page
{

    protected DataTable dt = createDT();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            //一次性加载 适用于小数据量
            TreeView2.Nodes.Clear();
            CreateLevelTreeView(TreeView2, dt, "module_name", "module_id", "module_fatherid");
            TreeView2.ExpandAll();

            //异步加载 适用于大数据量
            TreeView1.Nodes.Clear();
            DataView dv = dt.DefaultView;
            dv.RowFilter = " module_fatherid='0' ";            
            Bind_Root(dv.ToTable(), "module_name", "module_id");
        }

    }

    #region 异步加载TreeView
    /// <summary>
    /// 绑定父节点
    /// </summary>
    /// <param name="dt">数据源</param>
    /// <param name="text">text</param>
    /// <param name="value">value</param>
    private void Bind_Root(DataTable dt,string text,string value)
    {
        TreeNode tn;
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            tn = new TreeNode();
            tn.Value = dt.Rows[i][value].ToString();
            tn.Text = dt.Rows[i][text].ToString();
            //判断是否有子节点
            if (Check_Child(tn.Value))
            {
                tn.PopulateOnDemand = true;
                tn.Expanded = false;
            }
            TreeView1.Nodes.Add(tn);
        }
    }

    /// <summary>
    /// 绑定节点的子节点
    /// </summary>
    /// <param name="treeNode"></param>
    /// <param name="p"></param>
    private void Bind_Child(TreeNode treeNode, string fatherID, string text, string value)
    {
        TreeNode tn;
        DataRow[] drExist = dt.Select(" module_fatherid= '" + fatherID + "'");
        for (int i = 0; i < drExist.Length; i++)
        {
            tn = new TreeNode();
            tn.Value = drExist[i][value].ToString();
            tn.Text = drExist[i][text].ToString();
            //检验是否有子节点
            if (Check_Child(tn.Value))
            {
                tn.PopulateOnDemand = true;
                tn.Expanded = false;
            }
            treeNode.ChildNodes.Add(tn);
        }
    }

    /// <summary>
    /// 判断是否有子节点
    /// </summary>
    /// <param name="pre_Val">父类ID</param>
    /// <returns></returns>
    private bool Check_Child(string pre_Val)
    {
        DataRow[] dr = dt.Select(" module_fatherid= '" + pre_Val + "'");
        bool exist = (dr.Length > 0) ? true : false;
        return exist;
    }


    protected void TreeView1_TreeNodePopulate(object sender, TreeNodeEventArgs e)
    {
        Bind_Child(e.Node, e.Node.Value.ToString(), "module_name", "module_id");
    }
    #endregion

    #region 一次性加载TreeView
    /// <summary>   
    /// 创建无限分级目录树TreeView   
    /// </summary>   
    /// <param name="treeview">TreeView空间</param>   
    /// <param name="dt">数据源DataTable</param>   
    /// <param name="text">text字段</param>   
    /// <param name="value">value字段</param>   
    /// <param name="parentid">深度字段 例如parentid</param>   
    public static void CreateLevelTreeView(TreeView treeview, DataTable dt, string text, string value, string parentid)
    {
        DataView dv = dt.DefaultView;
        dv.RowFilter = parentid + " ='0'";
        foreach (DataRowView drv in dv)
        {
            TreeNode node = new TreeNode();
            node.Text = drv[text].ToString();
            node.Value = drv[value].ToString();
            node.Expanded = false;
            treeview.Nodes.Add(node);
            CreatTreeViewChildNode(dv, node, text, value, parentid);
        }
    }

    /// <summary>   
    /// 递归绑定子节点   
    /// </summary>   
    /// <param name="dv">源DataView</param>   
    /// <param name="parentNode">当前节点</param>   
    /// <param name="text">text字段</param>   
    /// <param name="value">value字段</param>   
    /// <param name="parentid">深度字段 例如parentid</param>   
    private static void CreatTreeViewChildNode(DataView dv, TreeNode parentNode, string text, string value, string parentid)
    {
        dv.RowFilter = parentid + " ='" + parentNode.Value + "' ";
        foreach (DataRowView row in dv)
        {
            TreeNode replyNode = new TreeNode();
            replyNode.Text = row[text].ToString();
            replyNode.Value = row[value].ToString();
            replyNode.Expanded = false;
            parentNode.ChildNodes.Add(replyNode);
            CreatTreeViewChildNode(dv, replyNode, text, value, parentid);
        }
    }  
    #endregion

    #region 创建数据
    private static DataTable createDT()
    {
        DataTable dt = new DataTable();
        dt.Columns.Add("module_id");
        dt.Columns.Add("module_name");
        dt.Columns.Add("module_fatherid");
        dt.Columns.Add("module_url");
        dt.Columns.Add("module_order");

        dt.Rows.Add("C1", "全国", "0", "", "1");
        dt.Rows.Add("M01", "广东", "C1", "", "1");

        dt.Rows.Add("M0101", "深圳", "M01", "", "100");
        dt.Rows.Add("M010101", "南山区", "M0101", "", "1000");
        dt.Rows.Add("M010102", "罗湖区", "M0101", "", "1001");
        dt.Rows.Add("M010103", "福田区", "M0101", "", "1002");
        dt.Rows.Add("M010104", "宝安区", "M0101", "", "1003");
        dt.Rows.Add("M010105", "龙岗区", "M0101", "", "1004");

        dt.Rows.Add("M01010301", "上梅林", "M010103", "", "1002001");
        dt.Rows.Add("M01010302", "下梅林", "M010103", "", "1002002");
        dt.Rows.Add("M01010303", "车公庙", "M010103", "", "1002003");
        dt.Rows.Add("M01010304", "竹子林", "M010103", "", "1002004");
        dt.Rows.Add("M01010305", "八卦岭", "M010103", "", "1002005");
        dt.Rows.Add("M01010306", "华强北", "M010103", "", "1002006");

        dt.Rows.Add("M0102", "广州", "M01", "", "101");
        dt.Rows.Add("M010201", "越秀区", "M0102", "", "1105");
        dt.Rows.Add("M010202", "海珠区", "M0102", "", "1106");
        dt.Rows.Add("M010203", "天河区", "M0102", "", "1107");
        dt.Rows.Add("M010204", "白云区", "M0102", "", "1108");
        dt.Rows.Add("M010205", "黄埔区", "M0102", "", "1109");
        dt.Rows.Add("M010206", "荔湾区", "M0102", "", "1110");
        dt.Rows.Add("M010207", "罗岗区", "M0102", "", "1111");
        dt.Rows.Add("M010208", "南沙区", "M0102", "", "1112");
        return dt;
    }
    #endregion
}


posted @ 2013-01-07 15:12  深南大道  阅读(157)  评论(0编辑  收藏  举报