MVC (Model-View-Controller) is a software architectural pattern commonly used for developing user interfaces. MVC 5 and MVC 6 refer to different versions of the ASP.NET MVC framework, which is used for building web applications on the .NET platform. Here are some key features of each:

MVC 5:

1. Controller Improvements:

• Attribute-based Routing: In MVC 5, you can define routes using attributes directly on controller actions, providing more control over the URL structure and making routing configuration more concise.

  // Controller with attribute-based routing 
  [RoutePrefix("api/products")] 
  public class ProductsController : Controller 
  { 
      [Route("{id}")] 
      public ActionResult GetProduct(int id) 
      { 
          // Get product logic 
      } 
  }
        

• Asynchronous Controller Actions: MVC 5 introduced support for asynchronous controller actions, allowing developers to write non-blocking code for I/O-bound operations, which can improve scalability and responsiveness.
• Improved Dependency Injection: MVC 5 made it easier to use DI containers like Autofac, Ninject, or Unity to manage dependencies in controllers and other components.

2. Bootstrap Integration:

• Bootstrap is a widely used front-end framework for creating responsive, mobile-first web applications.
• MVC 5 included built-in templates and helpers to facilitate the integration of Bootstrap components.

<!-- View with Bootstrap integration -->
@{
    ViewBag.Title = "Home";
}
<div class="container">
    <h1>Welcome to our website!</h1>
    <div class="alert alert-success" role="alert">
        This is a success message using Bootstrap styles.
    </div>
</div>

3. Authentication and Authorization:

• ASP.NET Identity: MVC 5 introduced ASP.NET Identity, a membership system that provides improved support for authentication, authorization, and user management.
• ASP.NET Identity is more flexible and extensible compared to the previous ASP.NET Membership system.

// Using ASP.NET Identity for authentication and authorization 
[Authorize(Roles = "Admin")] 
public ActionResult AdminDashboard() 
{ 
    // Admin dashboard logic 
}
  

4. Attribute Routing:

Attribute routing allows developers to define routes directly within the controller and action method using attributes like [Route], [HttpGet], [HttpPost], etc. This provides more flexibility compared to traditional route configuration in the RouteConfig class.

5. Filter Overrides:

• MVC 5 introduced the ability to override filters at various levels, including globally, controller-wide, and action-specific.

• Filters can be used to implement cross-cutting concerns such as logging, caching, exception handling, and authentication/authorization.

• The ability to override filters allows developers to customize filter behaviour for specific controllers or actions as needed.

MVC 6 (ASP.NET Core MVC):

1. Cross-Platform Support:

• ASP.NET Core MVC is a cross-platform framework that can run on Windows, Linux, and macOS.

• It is designed to be lightweight, modular, and scalable, making it suitable for a wide range of web application development scenarios.

2. Dependency Injection:

• ASP.NET Core MVC has built-in support for dependency injection, allowing developers to easily manage dependencies and promote modular and testable code.

• Dependency injection is a core feature of ASP.NET Core and is used throughout the framework for services like logging, configuration, and database access.

// Controller using dependency injection 
public class HomeController : Controller 
{ 
    private readonly ILogger _logger; 
 
    public HomeController(ILogger logger) 
    { 
        _logger = logger; 
    } 
    public IActionResult Index() 
    { 
        _logger.LogInformation("Index page accessed."); 
        return View(); 
    } 
}
  

3. Unified MVC and Web API:

• MVC 6 merges MVC and Web API into a single programming model, making it easier to build both web pages and APIs using the same framework.

• This unified approach simplifies development and reduces duplication of code between MVC controllers and Web API controllers.

// Controller with both MVC and Web API actions 
[Route("api/[controller]")] 
[ApiController] 
public class ProductsController : ControllerBase 
{ 
    [HttpGet] 
    public ActionResult> GetProducts() 
    { 
    } 
    [HttpPost] 
    public ActionResult CreateProduct(Product product) 
    { 
    } 
}
  

4. Modular Middleware Pipeline:

• ASP.NET Core introduced a modular middleware pipeline that allows developers to configure HTTP request processing using middleware components.

• Middleware components can be added to the pipeline to perform tasks such as request routing, authentication, authorization, logging, and error handling.

• The middleware pipeline provides more control and flexibility over how requests are handled compared to the traditional HTTP module pipeline used in previous versions of ASP.NET.

5. Razor Pages:

• Razor Pages is a new feature introduced in ASP.NET Core MVC that allows developers to build page-focused web applications with less ceremony compared to traditional MVC.

• Razor Pages combine the simplicity of Web Forms with the power and flexibility of Razor syntax, making it easier to create dynamic web pages with minimal code.

<!-- Razor Page example -->
@page
@{ 
ViewData["Title"] = "About";
}
<h2>@ViewData["Title"].</h2>
<p>@ViewData["Message"]</p>

6. Built-in Support for Modern Web Development:

• ASP.NET Core MVC comes with built-in support for modern web development techniques such as client-side development using frameworks like Angular, React, or Vue.js.

• The framework provides tools and templates for integrating client-side libraries and frameworks into ASP.NET Core applications, making it easier to build rich and interactive web experiences.

Conclusion:

Both MVC 5 and MVC 6 have their strengths and are suitable for different scenarios based on project requirements, team expertise, and platform compatibility. MVC 6 (ASP.NET Core MVC) represents a significant advancement with its cross-platform support, improved performance, and modularity, but migrating existing projects from MVC 5 to MVC 6 may require careful consideration and planning.