services.AddMvc().AddViewLocalization(Microsoft.AspNetCore.Mvc.Razor.LanguageViewLocationExpanderFormat.Suffix,
  opt => { opt.ResourcesPath = "Resources"; })

services.Configure(
 opts =>
 {
 var supportedCultures = new HashSet<CultureInfo>
 {
 CultureInfo.CurrentCulture,
 CultureInfo.CurrentUICulture,
 new CultureInfo("zh"),
 new CultureInfo("en"),
 };

 // Formatting numbers, dates, etc.
 opts.SupportedCultures = supportedCultures.ToList();
 //// UI strings that we have localized.
 opts.SupportedUICultures = supportedCultures.ToList();
 });

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
 var options = app.ApplicationServices.GetService>();
 app.UseRequestLocalization(options.Value);

 app.UseMvc();
}

@inject Microsoft.AspNetCore.Mvc.Localization.IViewLocalizer Lo
<fieldset>
 <legend>@Lo["Show following columns"]</legend>
 <div id="visibleColumnsForTable" class="loading-prompt" data-time="10"></div>
</fieldset>

public class YamlStringLocalizer : IHtmlLocalizer
{
 private readonly Dictionary languageDictionary = new Dictionary();

 public LocalizedString GetString(string name) { throw new NotImplementedException(); }

 public LocalizedString GetString(string name, params object[] arguments) { throw new NotImplementedException(); }

 public IEnumerable GetAllStrings(bool includeParentCultures) { throw new NotImplementedException(); }

 public IHtmlLocalizer WithCulture(CultureInfo culture) { throw new NotImplementedException(); }

 public LocalizedHtmlString this[string name]
 {
 get
 {
 var ci = CultureInfo.CurrentCulture;
 var languageName = ci.IsNeutralCulture "D:\Documents\Paradox Interactive\Stellaris\mod\cn\localisation\l.${languageName}.yml";
 if (languageDictionary.TryGetValue(languageName, out var content) == false)
 {
 if (File.Exists(path) == false)
  return new LocalizedHtmlString(name, name, true, path);

 content = File.ReadAllText(path);
 languageDictionary.Add(languageName, content);
 }

 var regex = new Regex(@"^\s*" + name + @":\s+""(.*""\s*$", RegexOptions.Multiline);
 var match = regex.Match(content);
 if (match.Success)
 {
 var value = match.Groups[1].Value;
 return new LocalizedHtmlString(name, value);
 }
 else
 {
 return new LocalizedHtmlString(name, name, true, path);
 }
 }
 }

 public LocalizedHtmlString this[string name, params object[] arguments] => throw new NotImplementedException();

}

@inject Microsoft.AspNetCore.Mvc.Localization.IViewLocalizer Lo
@inject YamlStringLocalizer YLo

public void ConfigureServices(IServiceCollection services)
{
 services.AddSingleton();

 services.AddMvc()
 .AddViewLocalization(Microsoft.AspNetCore.Mvc.Razor.LanguageViewLocationExpanderFormat.Suffix,
   opt => { opt.ResourcesPath = "Resources"; })

 ......
}