AspNetCore.Docs/aspnetcore/fundamentals/http-context.md

title	author	description	ms.author	ms.custom	ms.date	uid
Access HttpContext in ASP.NET Core	coderandhiker	Learn how to access HttpContext in ASP.NET Core.	riande	mvc	07/27/2018	fundamentals/httpcontext

Access HttpContext in ASP.NET Core

ASP.NET Core apps access the HttpContext through the IHttpContextAccessor interface and its default implementation HttpContextAccessor.

::: moniker range=">= aspnetcore-2.0"

Use HttpContext from Razor Pages

The Razor Pages PageModel exposes the HttpContext property:

public class AboutModel : PageModel
{
    public string Message { get; set; }

    public void OnGet()
    {
        Message = HttpContext.Request.PathBase;
    }
}

::: moniker-end

Use HttpContext from a Razor view

IHttpContextAccessor service access is provided to a Razor view via the @inject directive. The following example retrieves the current username in an Intranet app using Windows Authentication:

@using Microsoft.AspNetCore.Http
@inject IHttpContextAccessor HttpContextAccessor

@{
    var username = HttpContextAccessor.HttpContext.User.Identity.Name;
}

Use HttpContext from a controller

Controllers expose the ControllerBase.HttpContext property:

public class HomeController : Controller
{
    public IActionResult About()
    {
        var pathBase = HttpContext.Request.PathBase;
        // Do something with the PathBase.

        return View();
    }
}

Use HttpContext from middleware

When working with custom middleware components, HttpContext is passed into the Invoke or InvokeAsync method and can be accessed when the middleware is configured:

public class MyCustomMiddleware
{
    public Task InvokeAsync(HttpContext context)
    {
        // Middleware initialization optionally using HttpContext
    }
}

Use HttpContext from custom components

For other framework and custom components that require access to HttpContext, the recommended approach is to register a dependency using the built-in dependency injection container. The dependency injection container supplies the IHttpContextAccessor to any classes that declare it as a dependency in their constructors.

::: moniker range=">= aspnetcore-2.1"

public void ConfigureServices(IServiceCollection services)
{
     services.AddMvc()
         .SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
     services.AddHttpContextAccessor();
     services.AddTransient<IUserRepository, UserRepository>();
}

::: moniker-end

::: moniker range="<= aspnetcore-2.0"

public void ConfigureServices(IServiceCollection services)
{
     services.AddMvc();
     services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
     services.AddTransient<IUserRepository, UserRepository>();
}

::: moniker-end

In the preceding example:

• UserRepository declares its dependency on IHttpContextAccessor.
• The dependency is supplied when dependency injection resolves the dependency chain and creates an instance of UserRepository.

public class UserRepository : IUserRepository
{
    private readonly IHttpContextAccessor _httpContextAccessor;

    public UserRepository(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    public void LogCurrentUser()
    {
        var username = _httpContextAccessor.HttpContext.User.Identity.Name;
        service.LogAccessRequest(username);
    }
}