Creating Custom Controller

To create the custom controller factory you need to implement IControllerFactory Interface and register the class in global.asax. Bellow mention code explains how we can load a controller on the basis of browser language selection .

Example  

 customeControllerFactory.cs  
 using System;  
 using System.Collections.Generic;  
 using System.Linq;  
 using System.Web;  
 using System.Web.Mvc;  
 using System.Configuration;  
 using System.EnterpriseServices;  
 namespace MyViewEngine.CustomControllerFactory  
 {  
   public class customeControllerFactory : IControllerFactory  
   {  
     public IController CreateController(System.Web.Routing.RequestContext requestContext, string controllerName)  
     {  
       if (string.IsNullOrEmpty(controllerName))  
         throw new ArgumentNullException("controllerName");  
       string language = requestContext.HttpContext.Request.Headers["Accept-Language"];  
       string controllerType = string.Empty;  
       if (language == "fa-IR")  
         controllerType = string.Format(ConfigurationManager.AppSettings["FarsiControllerTypePattern"], controllerName+"Controller");  
       else  
         controllerType = string.Format(ConfigurationManager.AppSettings["EnglishControllerTypePattern"], controllerName + "Controller");  
       var t = Type.GetType(controllerType);  
       IController controller = Activator.CreateInstance(Type.GetType(controllerType)) as IController;  
       return controller;  
     }  
     public System.Web.SessionState.SessionStateBehavior GetControllerSessionBehavior(System.Web.Routing.RequestContext requestContext, string controllerName)  
     {  
       return System.Web.SessionState.SessionStateBehavior.Default;  
     }  
     public void ReleaseController(IController controller)  
     {  
       if (controller is IDisposable)  
         (controller as IDisposable).Dispose();  
       else  
         controller = null;  
     }  
   }  
 }  
 --------------------------------------------------------------------------------------------------------------  
 In Global.asax register on application start the code mark in red  
  protected void Application_Start()  
     {  
       AreaRegistration.RegisterAllAreas();  
       RegisterGlobalFilters(GlobalFilters.Filters);  
       RegisterRoutes(RouteTable.Routes);  
       ControllerBuilder.Current.SetControllerFactory(typeof(customeControllerFactory));  
     }  
 --------------------------------------------------------------------------------------------------------------  
 In application level web.config you need to add the following code  
 <appSettings>  
     <add key="EnglishControllerTypePattern" value="MyViewEngine.Controllers.En.{0}, CustomViewEngine"/>  
   <add key="FarsiControllerTypePattern" value="MyViewEngine.Controllers.Fa.{0}"/>  
  </appSettings>