Aspnet Mvc

title: ASP.NET Core MVC — Complete Guide to Model-View-Controller Pattern description: 'Learn ASP.NET Core MVC: controllers handle requests, models represent data, Razor views render HTML, routing maps URLs, and Tag Helpers simplify HTML generation.' date: 2026-06-28 lastmod: 2026-06-28 weight: 14 tags: [backend, aspnet]

ASP.NET Core MVC implements the Model-View-Controller pattern where Models handle data, Views render UI with Razor syntax, and Controllers process user requests and responses.

## What You'll Learn

By the end of this tutorial, you'll understand MVC architecture in ASP.NET Core, create models with validation, build views with Razor, implement controllers, and use Tag Helpers.

## Why MVC Matters

MVC separates concerns making code testable, maintainable, and scalable. ASP.NET Core MVC is the standard pattern for building web applications with clean separation of layers.

## Real-World Use

Stack Overflow uses ASP.NET Core MVC. Controllers handle requests, models manage data, and Razor views generate the HTML pages users see. Each layer can be tested independently.

## MVC Learning Path

```mermaid
flowchart LR
  A[Project Structure] --> B[MVC]
  B --> C[Controllers]
  C --> D[Views]
  D --> E[Models]
  B --> F{You Are Here}
  style F fill:#f90,color:#fff

Controller

using Microsoft.AspNetCore.Mvc;
namespace MyApp.Controllers;
public class ProductsController : Controller
{
    private readonly IProductService _productService;
    public ProductsController(IProductService productService)
    {
        _productService = productService;
    }
    public IActionResult Index()
    {
        var products = _productService.GetAllProducts();
        return View(products);  // Pass model to view
    }
    public IActionResult Details(int id)
    {
        var product = _productService.GetProductById(id);
        if (product == null)
            return NotFound();
        return View(product);
    }
}

Model

using System.ComponentModel.DataAnnotations;
namespace MyApp.Models;
public class Product
{
    public int Id { get; set; }
    [Required(ErrorMessage = "Name is required")]
    [StringLength(100)]
    public string Name { get; set; } = string.Empty;
    [Range(0.01, 10000)]
    public decimal Price { get; set; }
    [Display(Name = "Category")]
    public string? Category { get; set; }
}

Razor View

@model IEnumerable<MyApp.Models.Product>
<h1>Products</h1>
<table class="table">
    <thead>
        <tr>
            <th>@Html.DisplayNameFor(m => m.Name)</th>
            <th>@Html.DisplayNameFor(m => m.Price)</th>
            <th></th>
        </tr>
    </thead>
    <tbody>
        @foreach (var product in Model)
        {
            <tr>
                <td>@product.Name</td>
                <td>@product.Price.ToString("C")</td>
                <td>
                    <a asp-action="Details" asp-route-id="@product.Id">Details</a>
                </td>
            </tr>
        }
    </tbody>
</table>

Routing

// Program.cs - convention-based routing
app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

// Attribute routing on controller
[Route("products")]
public class ProductsController : Controller
{
    [HttpGet]  // GET /products
    public IActionResult Index() { ... }
    
    [HttpGet("{id:int}")]  // GET /products/5
    public IActionResult Details(int id) { ... }
}

Common Mistakes

1. Fat Controllers

Putting business logic in controllers violates MVC. Use services for business logic and keep controllers thin.

2. Not Using View Models

Passing domain models directly to views couples UI to data layer. Create dedicated ViewModels for presentation.

3. Ignoring Model Validation

Without [Required] and validation attributes, invalid data enters the system. Always validate with ModelState.IsValid.

4. Mixing Concerns in Views

Views should only render HTML. Don't put complex logic, database calls, or business rules in views.

5. Forgetting Anti-Forgery Tokens

POST forms need anti-forgery tokens. Use @Html.AntiForgeryToken() or the FormTagHelper which adds it automatically.

Practice Questions

1. What are the three components of MVC?

Model (data/business logic), View (presentation/UI), Controller (request handling/coordination).

2. How do you pass data from controller to view?

Return View(model) passes a model object. Use ViewBag or ViewData for additional data.

3. What is the role of a ViewModel?

A ViewModel shaped specifically for a view, containing only the properties the view needs.

4. How does routing work in ASP.NET Core MVC?

The router matches URL patterns to controller actions. Convention-based or attribute routing maps Requests to actions.

5. Challenge: Create a complete MVC CRUD for a Product model with validation and views.

FAQ

Mini Project: Product Catalog MVC

Build a product listing page with MVC.

dotnet new mvc -n ProductCatalog
cd ProductCatalog

// Models/Product.cs
public class Product {
    public int Id { get; set; }
    public string Name { get; set; } = "";
    public decimal Price { get; set; }
}
// Controllers/ProductsController.cs
public class ProductsController : Controller {
    public IActionResult Index() {
        var products = new List<Product> {
            new() { Id = 1, Name = "Laptop", Price = 999.99m },
            new() { Id = 2, Name = "Mouse", Price = 29.99m }
        };
        return View(products);
    }
}

What's Next

ASP.NET Core Controllers ASP.NET Core Views