MSDN Documentation

ASP.NET MVC Overview

ASP.NET MVC is a framework for building dynamic websites and web applications using the Model-View-Controller (MVC) architectural pattern. It offers a clean separation of concerns, making your code more organized, maintainable, and testable.

Key Benefits

• Separation of Concerns: Divides an application into three interconnected components: Model, View, and Controller.
• Testability: The clear separation of concerns makes it easier to unit test individual components.
• Flexibility: Supports various development workflows and allows for greater control over HTML output.
• Leverages existing .NET features: Builds upon the powerful .NET platform, including its rich libraries and tools.

The MVC Pattern Explained

The Model-View-Controller (MVC) pattern is an architectural design pattern that separates an application into three distinct parts:

Here's a simplified flow:

1. A user interacts with the application (e.g., clicks a link).
2. The request is routed to a specific Controller action.
3. The Controller may interact with the Model to retrieve or update data.
4. The Controller selects a View to render the response.
5. The View uses the data from the Model to generate the UI (typically HTML).
6. The generated UI is sent back to the user's browser.

Core Components

Model

The Model represents the application's data and the rules that govern that data. It's responsible for:

• Encapsulating the application's state.
• Implementing the business logic.
• Responding to requests for information about its state.
• Responding to instructions to change its state.

For example, a Product class could represent a product in an e-commerce application.

public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
}
                

View

The View is responsible for presenting data to the user. It's typically implemented using:

• Razor syntax (.cshtml files) for dynamic content generation.
• HTML, CSS, and JavaScript for the user interface.

Views don't contain business logic; they simply display data provided by the Controller and send user input back to the Controller.

<h1>Product Details</h1>

<p>Name: @Model.Name</p>
<p>Price: @Model.Price.ToString("C")</p>
                

Controller

The Controller acts as an intermediary between the Model and the View. It:

• Handles incoming HTTP requests.
• Interacts with the Model to perform operations (e.g., fetch data, save data).
• Selects the appropriate View to render the response.
• Passes data from the Model to the View.

Controllers are C# classes that inherit from System.Web.Mvc.Controller or Microsoft.AspNetCore.Mvc.Controller.

using System.Web.Mvc;

public class ProductController : Controller
{
    public ActionResult Details(int id)
    {
        // In a real app, this would fetch data from a database
        var product = new Product
        {
            Id = id,
            Name = "Example Widget",
            Price = 19.99m
        };

        return View(product); // Renders the Product/Details.cshtml view
    }
}
                

Routing

ASP.NET MVC uses a powerful routing system to map incoming URLs to specific Controller actions. This allows for clean, SEO-friendly URLs.

For example, a URL like /Product/Details/5 might map to the Details action in the ProductController, with 5 as the product ID.

Getting Started

To start building ASP.NET MVC applications, you can use Visual Studio and the ASP.NET MVC project template. This template provides a basic structure with pre-configured Models, Views, Controllers, and routing.

Explore the following resources for more in-depth information:

• Deeper Dive into MVC Architecture
• Tutorial: Creating Your First ASP.NET MVC Application