Follow the below steps:

Step 1: Set Up Resource Files
1. Create Resource Files: Start by creating resource files (.resx) for each language you want to support. For example:
   - `AppResources.resx` (default, for English)
   - `AppResources.sw.resx` (for Swahili)

2. Add Key-Value Pairs: In each resource file, define key-value pairs for the strings you want to localize. For instance:
   - `Greeting` with value `Hello`
   - `WelcomeMessage` with value `Welcome to our website`

Step 2: Implement Language Switching
1. Create a Language Controller: Create a controller to handle language switching. For example, `LanguageController`.

2. Define Action Method: In `LanguageController`, define an action method to set the selected language in a session variable or a cookie. This method will be triggered when you change the language from the dropdown.

   
   public class LanguageController : Controller
   {
       public ActionResult ChangeLanguage(string lang)
       {
           // Set the selected language in session or cookie
           Session["CurrentCulture"] = lang;
           return Redirect(Request.UrlReferrer.ToString());
       }
   }
   

 Step 3: Update Controller and Views
1. Controller Base Class: Update your base controller class (e.g., `ControllerBase`) to override `ExecuteCore` method to set the thread's culture based on the session/cookie value.

  
   public class ControllerBase : Controller
   {
       protected override void ExecuteCore()
       {
           string cultureName = Session["CurrentCulture"] as string;
           cultureName = cultureName ?? "en"; // Default to English if no language is selected
           
           Thread.CurrentThread.CurrentCulture = new CultureInfo(cultureName);
           Thread.CurrentThread.CurrentUICulture = new CultureInfo(cultureName);
           
           base.ExecuteCore();
       }
   }
   

2. Update Views: Use resource files in your views to display localized strings. Access localized strings using `@Resources.AppResources.StringKey`.

Step 4: Add Dropdown in Layout
1. Add Dropdown: In your layout (e.g., `_Layout.cshtml`), add a dropdown to select the language.

   
   

       
           English
           Swahili
           
       
   

   

Step 5: Apply Localization
1. Use Localized Strings: Replace hard-coded strings in your views with localized strings from resource files.

  
   

@Resources.AppResources.Greeting

   

@Resources.AppResources.WelcomeMessage

   

Thanks

Thank you, sir, for your help and time. I have a question for this 

1. Create Resource Files: Generate resource files for each language you want to support (e.g., English and Swahili).

Do I have to create all these key-value pairs manually?

To achieve language localization in your .NET MVC project, you can utilize resource files for storing language-specific content. Here's a simplified guide to help you implement this feature:

1. Create Resource Files: Generate resource files for each language you want to support (e.g., English and Swahili).

2. Set Culture in Global.asax: In the Application_Start method of Global.asax, set the culture based on the selected language.

3. Change Language: Implement a dropdown menu in your view to allow users to select the language.

4. Switch Language: Based on the selected language, update the culture in the controller action.

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    // Set default culture
    CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("en-US");
    CultureInfo.DefaultThreadCurrentUICulture = new CultureInfo("en-US");
    // Other configurations
    RouteConfig.RegisterRoutes(RouteTable.Routes);
}