On demand file : TreeView « Data Binding « ASP.NET Tutorial






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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TreeView ID="TreeView1" OnTreeNodePopulate="PopulateNode" runat="server" ExpandDepth="0">
            <Nodes>
                <asp:TreeNode PopulateOnDemand="True" Text="Demos" Value="Demos"></asp:TreeNode>
            </Nodes>
        </asp:TreeView>
    
    </div>
    </form>
</body>
</html>

File: Default.aspx.cs

using System;
using System.Collections;
using System.Data;
using System.Data.Common;
using System.Configuration;
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.IO;

public partial class OnDemandFiles : System.Web.UI.Page
{
  static readonly char[] _slashArray = new char[] { '/' };

  protected void PopulateNode(Object source, TreeNodeEventArgs e)
  {
    TreeNode node = e.Node;
    if (node.Value == "Demos")
      node.Value = "~/";

    String rootDirectory = Request.MapPath("~/", Request.ApplicationPath, false);
    String fullPath = Request.MapPath(node.Value, Request.ApplicationPath, false);

    if (fullPath.StartsWith(rootDirectory) == false)
    {
      return;
    }

    String[] dirs = Directory.GetDirectories(fullPath);

    foreach (String dir in dirs)
    {
      String virtualDir = node.Value.TrimEnd(_slashArray) + "/" + Path.GetFileName(dir);

      TreeNode newNode = new TreeNode(Path.GetFileName(dir), virtualDir);
      if (Directory.GetFiles(dir).Length > 0
          || Directory.GetDirectories(dir).Length > 0)
      {
        newNode.PopulateOnDemand = true;
      }
      node.ChildNodes.Add(newNode);
    }

    String[] files = Directory.GetFiles(fullPath);
    foreach (String file in files)
    {
      TreeNode newNode = new TreeNode(Path.GetFileName(file), Path.GetFileName(file));
      node.ChildNodes.Add(newNode);
    }
  }
}








19.26.TreeView
19.26.1.The ASP.NET 3.5 Framework includes two hierarchical DataBound controls
19.26.2.Fibonacci Tree On Demand
19.26.3.On demand file