ASP.NET

<%@ WebHandler Language="C#" Class="Handler" %>
        
using System;
using System.Web;
using System.Web.SessionState;
          
public class Handler : IHttpHandler, IRequiresSessionState  
{
    public void ProcessRequest (HttpContext context) {

        if (context.Session["SessionName"] == null)
            context.Session["SessionName"] = 0;
                                  
        int counter = (int)context.Session["SessionName"];
        counter++;
        context.Session["SessionName"] = counter;
                             
        context.Response.ContentType = "text/plain";
        context.Response.Write("Counter: " + context.Session["SessionName"]);
    }
        
    public bool IsReusable {
        get {
            return false;
        }
    }
}

   Sub SaveNodes(ByVal nodesCollection As TreeNodeCollection, ByVal textWriter As System.Xml.XmlTextWriter)
      Dim link_node As TreeNode
      For Each link_node In nodesCollection
         If link_node.ChildNodes.Count Then
            textWriter.WriteStartElement("Folder")
            textWriter.WriteAttributeString("Name", link_node.Text)
            textWriter.WriteRaw(vbCrLf)
         Else
            textWriter.WriteStartElement("Link")
            textWriter.WriteAttributeString("Name", link_node.Text)
            textWriter.WriteAttributeString("Location", link_node.NavigateUrl)
         End If

         If link_node.ChildNodes.Count > 0 Then
            SaveNodes(link_node.ChildNodes, textWriter)
         End If
         textWriter.WriteEndElement()
         textWriter.WriteRaw(vbCrLf)
      Next
   End Sub

   Sub SaveTreeViewData(ByVal treeView As TreeView, ByVal path As String)
      'Create a serializer and file to save TreeViewData
      Dim TextWriter As New System.Xml.XmlTextWriter(path, System.Text.Encoding.UTF8)

      TextWriter.WriteStartDocument()
      TextWriter.WriteRaw(vbCrLf)

      SaveNodes(treeView.Nodes, TextWriter)

      TextWriter.Close()
   End Sub


   Protected Sub Save_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Save.Click
      SaveTreeViewData(Link_Tree, "favorites.xml")
End Sub

// bind the grid
DataTable dt = GetMyData();
MyDataGrid.DataSource = dt;
MyDataGrid.DataBind();

// inspect the table for the number of columns
int numColumns = dt.Columns.Count;

void MyDataBound(Object o, EventArgs e)
{
    // add a special heading at the top of the gridview table;
    // assumes gv is the id of the gridview
    
    Table t = gv.Controls[0] as Table
    if (t != null)
    {
        GridViewRow heading = new GridViewRow(0, -1
                      , DataControlRowType.Header
                      , DataControlRowState.Normal
                      );

        // add cell(s) to the heading row                      
        // in this example, I'm just adding one that will span
        // all the columns of the row
        
        TableCell cell = New TableCell();
        cell.Text = "My Spanning Heading";
        cell.ColumnSpan = gv.Rows(0).Cells.Count;
        
        // make it the same heading style as the gridview
        cell.MergeStyle(gv.HeaderStyle);
        
        // add it to the new heading row
        heading.Cells.Add(cell);
        
        // and add the new heading row to the top of the gridview
        t.Rows.AddAt(0, heading);
    }   
}

<asp:GridView ID="gv" runat="server"
              OnDataBound="MyDataBound" 
              />