ASP.NET Session

last modified April 3, 2025

In this article, we explore Session state management in ASP.NET 8. Session allows storing user-specific data across multiple HTTP requests.

ASP.NET Session provides a way to persist user data during a browsing session. It's essential for maintaining state in stateless HTTP protocol applications.

Basic Definition

Session in ASP.NET is a server-side state management mechanism. It stores data specific to a user's browsing session on the web server.

Each user gets a unique session identified by a Session ID. This ID is typically stored in a cookie or passed via URL for cookie-less sessions.

Session data is stored in memory by default but can be configured to use distributed caches or databases. It's ideal for user-specific temporary data.

Session state is maintained for each user separately. The data persists until the session expires or is explicitly abandoned.

ASP.NET Session Example

The following example demonstrates basic Session usage in an ASP.NET Core MVC application.

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();

// Add session support with configuration
builder.Services.AddSession(options =>
{
    options.IdleTimeout = TimeSpan.FromMinutes(30);
    options.Cookie.HttpOnly = true;
    options.Cookie.IsEssential = true;
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

// Enable session middleware
app.UseSession();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

This sets up a basic ASP.NET MVC application with Session support. The AddSession method configures session options like timeout.

using Microsoft.AspNetCore.Mvc;

public class SessionController : Controller
{
    public IActionResult Index()
    {
        // Retrieve visit count from session or initialize
        int visitCount = HttpContext.Session.GetInt32("VisitCount") ?? 0;
        visitCount++;
        
        // Store updated count in session
        HttpContext.Session.SetInt32("VisitCount", visitCount);
        
        // Store current timestamp
        HttpContext.Session.SetString("LastVisit", DateTime.Now.ToString());
        
        ViewBag.VisitCount = visitCount;
        ViewBag.LastVisit = HttpContext.Session.GetString("LastVisit");
        
        return View();
    }
    
    public IActionResult ClearSession()
    {
        HttpContext.Session.Clear();
        return RedirectToAction("Index");
    }
}

This controller demonstrates basic Session operations. The Index action tracks page visits by storing a counter in Session.

@{
    ViewData["Title"] = "Session Demo";
}

<h2>Session Demo</h2>

<p>You have visited this page @ViewBag.VisitCount times.</p>
<p>Your last visit was at @ViewBag.LastVisit</p>

<a asp-action="ClearSession" class="btn btn-danger">Clear Session</a>

The view displays the session data and provides a button to clear the session. Session values are accessed through the ViewBag populated by the controller.

This example shows basic Session operations: storing and retrieving simple data types. The session persists across requests until cleared or expired.

Source

Microsoft ASP.NET Session Documentation

In this article, we have explored Session state management in ASP.NET 8. This powerful feature enables maintaining user-specific data across requests.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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