Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Web
Imports System.Security.Principal

Namespace Samples.Aspnet.HttpModuleExamples

    Public Class RequestTimeIntervalModule
        Implements IHttpModule

        Public Sub Dispose() Implements IHttpModule.Dispose
        End Sub

        ' Add event handlers to the HttpApplication.
        Public Sub Init(ByVal httpApp As HttpApplication) Implements IHttpModule.Init
            AddHandler httpApp.BeginRequest, AddressOf OnBeginRequest
            AddHandler httpApp.EndRequest, AddressOf OnEndRequest
        End Sub

        ' Record the time of the begin request event.
        Public Sub OnBeginRequest(ByVal sender As [Object], ByVal e As EventArgs)
            Dim httpApp As HttpApplication = sender
            httpApp.Context.Items("beginRequestTime") = DateTime.Now
        End Sub

        Public Sub OnEndRequest(ByVal sender As [Object], ByVal e As EventArgs)
            Dim httpApp As HttpApplication = sender
            Dim beginRequestTime As DateTime = _
                CType(httpApp.Context.Items("beginRequestTime"), DateTime)
            ' Evaluate the time between the begin and the end request events.
            Dim ts As TimeSpan = DateTime.Now - beginRequestTime
            ' Write the time span out as a response header.
            httpApp.Context.Response.AppendHeader("TimeSpan", ts.ToString())
            ' Get the current user's ID.
            Dim user As String = WindowsIdentity.GetCurrent().Name

            ' Display the information in the page.
            Dim sb As New StringBuilder
            sb.AppendLine("<H2>RequestTimeInterval HTTP Module Output</H2>")
            sb.AppendLine("Current user: ")
            sb.AppendLine(user)
            sb.AppendLine("<br/>Time span between begin-request and end-request events: ")
            sb.AppendLine(ts.ToString())

            httpApp.Context.Response.Output.WriteLine(sb.ToString)
        End Sub
    End Class

End Namespace

using System;
using System.Collections.Generic;
using System.Text;
using System.Web;
using System.Security.Principal;

namespace Samples.Aspnet.HttpModuleExamples
{
    public class RequestTimeIntervalModule : IHttpModule
    {
        public void Dispose()
        {
        }

        // Add event handlers to the HttpApplication.
        public void Init(HttpApplication httpApp)
        {
            httpApp.BeginRequest += new EventHandler(OnBeginRequest);
            httpApp.EndRequest += new EventHandler(OnEndRequest);
        }

        // Record the time of the begin request event.
        public void OnBeginRequest(Object sender, EventArgs e)
        {
            HttpApplication httpApp = (HttpApplication)sender;
            httpApp.Context.Items["beginRequestTime"] = DateTime.Now;
        }

        public void OnEndRequest(Object sender, EventArgs e)
        {
            HttpApplication httpApp = (HttpApplication)sender;
            
            // Get the time of the begin request event.
            DateTime beginRequestTime =
                (DateTime)httpApp.Context.Items["beginRequestTime"];
            
            // Evaluate the time between the begin and the end request events.
            TimeSpan ts = DateTime.Now - beginRequestTime;
            
            // Write the time span out as a request header.
            httpApp.Context.Response.AppendHeader("TimeSpan", ts.ToString());
            
            // Get the current user's ID.
            string user = WindowsIdentity.GetCurrent().Name;

            // Display the information in the page.
            StringBuilder sb = new StringBuilder();
            sb.AppendLine("<H2>RequestTimeInterval HTTP Module Output</H2>");
            sb.AppendFormat("Current user: {0}<br/>", user);
            sb.AppendFormat("Time span between begin-request and end-request events: {0}<br/>", 
                ts.ToString());

            httpApp.Context.Response.Output.WriteLine(sb.ToString());

        }

    }
}