@using Microsoft.AspNetCore.Builder
@using Microsoft.AspNetCore.Http.Extensions
@using Microsoft.AspNetCore.Http.Features
@using Microsoft.AspNetCore.Localization
@using Microsoft.AspNetCore.Mvc.Localization
@using Microsoft.Extensions.Options

@inject IViewLocalizer Localizer
@inject IOptions<RequestLocalizationOptions> LocOptions

@{
    var requestCulture = Context.Features.Get<IRequestCultureFeature>();
    var cultureItems = LocOptions.Value.SupportedUICultures
        .Select(c => new SelectListItem { Value = c.Name, Text = c.DisplayName })
        .ToList();
    var returnUrl = string.IsNullOrEmpty(Context.Request.Path) ? "~/" : $"~{UriHelper.BuildRelative(Context.Request.PathBase, Context.Request.Path, Context.Request.QueryString)}";
}

<div title="@Localizer["Request culture provider:"] @requestCulture?.Provider?.GetType().Name">
    <form cb-preventsubmit id="selectLanguage" asp-controller="Home" asp-action="SetLanguage" asp-route-returnUrl="@returnUrl" method="post" class="form-horizontal" role="form">
        
        <div class="input-group">
            <span class="input-group-text">
                    <i class="fa fa-language"></i>
                </span>
            <select class="form-control" name="culture" onchange="this.form.submit();" asp-for="@requestCulture.RequestCulture.UICulture.Name" asp-items="cultureItems"></select>
        </div>
    </form>
</div>