MVC4 Multi-language

Application Resources can be created in ASP.NET applications with two different scopes, depending on the level you want to share these resources across the application

In this example we will create a set of global resources containing dictionaries for the application display in three different languages: English (en), Spanish (es), and Catalán (ca)

The application we will build is a data-entry form based on Guest model, and will be displayed in the selected language

    public class Guest
    {
        [Required(ErrorMessageResourceType = typeof(Resources.Dictionary), 
         ErrorMessageResourceName="RequiredFirstName")]
        public string FirstName { get; set; }

        [Required(ErrorMessageResourceType = typeof(Resources.Dictionary), 
         ErrorMessageResourceName = "RequiredLastName")]
        public string LastName { get; set; }

        [DataType(DataType.Date)]
        [DisplayFormat(DataFormatString = "{0:d}")]
        public DateTime? BirthDate { get; set; }
    }

We will add the next div element to the _layout.cshtml view in order to generate the language selector

    <div class="content-wrapper">
        @{
            CultureInfo currentCulture = Thread.CurrentThread.CurrentCulture;
            string selectedLanguageStyle = "background-color:#FFDAA3;font-weight:bold;";
            <div class="float-right">                        
            @switch (currentCulture.TwoLetterISOLanguageName)
            {
                case "en":
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "en-US" })'>English</a>
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "es-ES" })'>Spanish</a>
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "ca-ES" })'>Catalán</a>
                    break;
                case "es":
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "en-US" })'>English</a>
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "es-ES" })'>Spanish</a>
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "ca-ES" })'>Catalán</a>
                    break;
                case "ca":
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "en-US" })'>English</a>
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "es-ES" })'>Spanish</a>
                    <a href='@Url.Action("ChangeLanguage", 
                                            "Home", new { culture = "ca-ES" })'>Catalán</a>
                    break;
            }
            </div>
        }
    </div>

This is the action method called from the language selectors (anchor elements), inside the HomeController

    public ActionResult ChangeLanguage(string culture)
    {
        Thread.CurrentThread.CurrentUICulture = new CultureInfo(culture);
        Thread.CurrentThread.CurrentCulture = Thread.CurrentThread.CurrentUICulture;

        Session["lang"] = culture;

        return Redirect(Request.UrlReferrer.ToString());
    }

The approach is this: we will create a BaseController to handle the ExecuteCore method, and stablish the thread's current culture. ExecuteCore method invokes the action in the current controller context. The controllers in our application will inherit BaseController

    public class BaseController : Controller
    {
        //
        // GET: /Base/

        protected override void ExecuteCore()
        {
            var culture = Session["lang"] ?? "en-US";        

            Thread.CurrentThread.CurrentUICulture = new CultureInfo(culture.ToString());
            Thread.CurrentThread.CurrentCulture = Thread.CurrentThread.CurrentUICulture;

            base.ExecuteCore();
        }

        protected override bool DisableAsyncSupport
        {
            get { return true; }
        }
    }

DysableAsyncSupport property gets whether to disable the asynchronous support for the controller. This flag is for backwards compatibility. ASP.NET MVC 4. allows a controller to support asynchronous patterns. This means ExecuteCore doesn't get called on derived classes. Derived classes can override this flag and set to true if they still need ExecuteCore to be called

The strongly-typed view based on Guest model is this:

@model MvcApp1.Models.Guest

@{
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>@Resources.Dictionary.ViewTitle</h2>

<div>
    @using (Html.BeginForm())
    {
        @Html.ValidationSummary(true)
        <table>
            <tbody>
                <tr>
                    <td>
                        <div class="editor-field">
                            <span>@Resources.Dictionary.FirstName</span>
                        </div>                        
                    </td>
                    <td>
                        @Html.EditorFor(model => model.FirstName)
                        @Html.ValidationMessageFor(model => model.FirstName)                        
                    </td>
                </tr>
                <tr>
                    <td>
                        <div class="editor-field">
                            <span>@Resources.Dictionary.LastName</span>
                        </div>                        
                    </td>
                    <td>
                        @Html.EditorFor(model => model.LastName)
                        @Html.ValidationMessageFor(model => model.LastName)                        
                    </td>
                </tr>
                <tr>
                    <td>
                        <div class="editor-field">
                            <span>@Resources.Dictionary.BirthDate</span>
                        </div>                        
                    </td>
                    <td>
                        @Html.EditorFor(model => model.BirthDate)
                    </td>
                </tr>
            </tbody>
        </table>
        <input type="submit" value="Save"/>
    }    
</div>

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

The result is the next:

<METHOD SOFTWARE © 2014>