Use same `.resx` file in ASP.NET Core and .NET Core console project

Question

I've implemented localization in ASP.NET Core according to this: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/localization

I have a common library project (MyProject.Common) where I keep the resource file (since it is used by multiple ASP.NET Core applications).

So I have a .resx file under MyProject.Common\Resources\Localization\SharedResources.sv.resx:

<?xml version="1.0" encoding="utf-8"?>
<root>
  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
    <xsd:element name="root" msdata:IsDataSet="true">
      <xsd:complexType>
        <xsd:choice maxOccurs="unbounded">
          <xsd:element name="metadata">
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="value" type="xsd:string" minOccurs="0" />
              </xsd:sequence>
              <xsd:attribute name="name" use="required" type="xsd:string" />
              <xsd:attribute name="type" type="xsd:string" />
              <xsd:attribute name="mimetype" type="xsd:string" />
              <xsd:attribute ref="xml:space" />
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="assembly">
            <xsd:complexType>
              <xsd:attribute name="alias" type="xsd:string" />
              <xsd:attribute name="name" type="xsd:string" />
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="data">
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
              </xsd:sequence>
              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
              <xsd:attribute ref="xml:space" />
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="resheader">
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
              </xsd:sequence>
              <xsd:attribute name="name" type="xsd:string" use="required" />
            </xsd:complexType>
          </xsd:element>
        </xsd:choice>
      </xsd:complexType>
    </xsd:element>
  </xsd:schema>
  <resheader name="resmimetype">
    <value>text/microsoft-resx</value>
  </resheader>
  <resheader name="version">
    <value>2.0</value>
  </resheader>
  <resheader name="reader">
    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
  </resheader>
  <resheader name="writer">
    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
  </resheader>
  <data name="English string" xml:space="preserve">
    <value>Swedish string</value>
  </data>
</root>

And I have an empty .cs file under MyProject.Common\Localization\SharedResources.cs that looks like this:

namespace MyProject.Common.Localization
{
    /// <summary>
    /// This is just a placeholder so that we can have all our resources in the same .resx file
    /// </summary>
    public class SharedResources
    {
    }
}

I have a class called Localizer that I use to get translated strings:

using System;
using Microsoft.Extensions.Localization;

namespace MyProject.Common.Localization
{
    public class Localizer
    {
        private readonly IStringLocalizer _localizer;

        public Localizer(IStringLocalizer<SharedResources> localizer)
        {
            _localizer = localizer;
        }

        public virtual LocalizedString this[string name]
        {
            get
            {
                if (name == null)
                {
                    throw new ArgumentNullException(nameof(name));
                }

                return _localizer[name];
            }
        }

        public virtual LocalizedString this[string name, params object[] arguments]
        {
            get
            {
                if (name == null)
                {
                    throw new ArgumentNullException(nameof(name));
                }

                return _localizer[name, arguments];
            }
        }
    }
}

And it is used liked this (will return swedish translation if culture of the request is swedish):

_localizer["English string"];

In Startup.cs for each of the ASP.NET Core projects I configure localization like this:

services
    // Add the localization services to the services container
    .AddLocalization(options => options.ResourcesPath = "Resources")

    // Configure supported cultures and localization options
    .Configure<RequestLocalizationOptions>(options =>
    {
        var supportedCultures = new[]
        {
            new CultureInfo("en"),
            new CultureInfo("sv")
        };

        // State what the default culture for your application is. This will be used if no specific culture
        // can be determined for a given request.
        options.DefaultRequestCulture = new RequestCulture(culture: "en", uiCulture: "en");

        // You must explicitly state which cultures your application supports.
        // These are the cultures the app supports for formatting numbers, dates, etc.
        options.SupportedCultures = supportedCultures;

        // These are the cultures the app supports for UI strings, i.e. we have localized resources for.
        options.SupportedUICultures = supportedCultures;
    });

I'm trying to figure out how to reuse this in a (.NET Core) console application? If I try to use my custom Localizer via dependency injection, I get: 'Unable to resolve service for type 'Microsoft.AspNetCore.Hosting.IHostingEnvironment' while attempting to activate 'Microsoft.Extensions.Localization.ResourceManagerStringLocalizerFactory. So this is because Microsoft.Extensions.Localization is dependent on ASP.NET Core, which doesn't exist in my console project.

How can I use the same .resx file in my console project?

Answer 1

I know I'm a bit late to the party here but you should be able to access your translations directly. Of course in a console app there is no such concept as request localization, so you'll need to manually handle culture lookup/storage/whatever, but once you know the culture it is possible to access your translations like this (no dependency injection required!):

var german = new System.Globalization.CultureInfo("de-DE");
var english = new System.Globalization.CultureInfo("en-AU");

// result "Guten tag"
var greeting1 = Shared.Resources.Lang.ResourceManager.GetString("GREETING", german); 

// result "Gidday mate"
var greeting2 = Shared.Resources.Lang.ResourceManager.GetString("GREETING", english);

You can probably figure out a nice way to handle language codes and resource tokens, but this should be enough to do your translations common resource files.

NOTE: this works in .Net Core 2.0, haven't tested in other versions.