HttpContext.Current.Features.Get<IRequestCultureFeature>() is null in asp.net Core

Question

I am trying to get the current culture from a user class in ASP.NET Core 1.1.

I have the following under ConfigureServices in Startup.cs :

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
services.Configure<RequestLocalizationOptions>(options =>
{
    var supportedCultures = new List<CultureInfo>
    {
        new CultureInfo("en-US"),
        new CultureInfo("fil-PH")
    };

    options.DefaultRequestCulture = new RequestCulture(culture: "en-US", uiCulture: "en-US");
    options.SupportedCultures = supportedCultures;
    options.SupportedUICultures = supportedCultures;
});

I have the following under Configure in Startup.cs :

IHttpContextAccessor httpContextAccessor = app.ApplicationServices.GetRequiredService<IHttpContextAccessor>();
Extensions.Context.Configure(httpContextAccessor);

IOptions<RequestLocalizationOptions>  localizationOptions = app.ApplicationServices.GetService<IOptions<RequestLocalizationOptions>>();
app.UseRequestLocalization(localizationOptions.Value);

I have the following user class:

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Features;
using Microsoft.AspNetCore.Localization;
using System;
using System.Globalization;

namespace Framework.Extensions
{
    public class Context
    {
        public HttpContext Current { get; set; }
        public Uri AbsoluteUri { get; set; }
        public string AbsolutePath { get; set; }
        public string Url { get; set; }
        public CultureInfo Culture { get; set; }

        private static IHttpContextAccessor HttpContextAccessor;
        public static void Configure(IHttpContextAccessor httpContextAccessor)
        {
            HttpContextAccessor = httpContextAccessor;
        }

        public Context()
        {
            Current = HttpContextAccessor.HttpContext;
            AbsoluteUri = GetAbsoluteUri();
            AbsolutePath = GetAbsoluteUri().AbsolutePath;
            Url = GetAbsoluteUri().ToString();
            Culture = GetCultureInfo();
        }

        private Uri GetAbsoluteUri()
        {
            UriBuilder uriBuilder = new UriBuilder();
            uriBuilder.Scheme = Current.Request.Scheme;
            uriBuilder.Host = Current.Request.Host.Host.ToString();
            if (Current.Request.Host.Port != null)
            {
                uriBuilder.Port = Current.Request.Host.Port ?? default(int);
            }
            uriBuilder.Path = Current.Request.Path.ToString();
            uriBuilder.Query = Current.Request.QueryString.ToString();
            Uri absoluteUri = uriBuilder.Uri;
            return uriBuilder.Uri;
        }

        private CultureInfo GetCultureInfo() {
            IFeatureCollection requestFeatures = Current.Features; /* POPULATED */
            RequestCultureFeature requestCultureFeature = requestFeatures.Get<RequestCultureFeature>(); /* NULL */
            RequestCulture requestCulture = requestCultureFeature.RequestCulture;
            return requestCulture.Culture;
        }
    }
}

Looking at the GetCultureInfo() method, Current appears to be correctly populated with info as I can see things like the host and port, etc. Features is also populated - at least not null. But calling Get<RequestCultureFeature>() on the Features is null?

Any ideas at why this would be empty, and how to fix it?

The reason I am trying to access it is to get the CurrentUICulture.

Answer 1

Try creating a parameterized constructor in Context class with IOptions<RequestLocalizationOptions> and once you register the RequestLocalizationOptions for Dependency Injection Service inside ConfigureServices of Startup.cs , framework will provide the registered instance into the Context class.

As you suggested concluding our comments here in case if it would be useful for someone else as well.

Answer 2

if your UseRequestLocalization() is coming after the call for UseMvc() try to Call UseRequestLocalization() before UseMvc() . and use the following code

var requestCulture = Context.Features.Get<IRequestCultureFeature>();

Answer 3

Looks like you aren't registering the RequestLocalizationMiddleware middleware:

app.UseRequestLocalization() is the extension method that should add the middleware, which will set the feature for you.

Answer 4

The right answer for the initial question has been provided by @shikyo:

The reason Get<RequestCultureFeature>() is null is because you need to use Get<IRequestCultureFeature>() the interface instead of the implementation.

The answer by @Siva-Gopal has some sense but the results are slightly different.