ASP.NET MVC Web Development

Create a new ASP.NET MVC project with essential components:

CSHARP
// Models/Product.cs
public class Product
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
    public DateTime CreatedAt { get; set; }
}

// Controllers/ProductController.cs
public class ProductController : Controller
{
    private readonly ApplicationDbContext _context;
    
    public ProductController(ApplicationDbContext context)
    {
        _context = context;
    }
    
    public async Task<IActionResult> Index()
    {
        var products = await _context.Products.ToListAsync();
        return View(products);
    }
    
    [HttpPost]
    public async Task<IActionResult> Create(Product product)
    {
        if (ModelState.IsValid)
        {
            _context.Products.Add(product);
            await _context.SaveChangesAsync();
            return RedirectToAction("Index");
        }
        return View(product);
    }
}

Progress:

• Set up project structure (Models, Views, Controllers)
• Configure database context and connection string
• Create models with data annotations
• Implement controllers with action methods
• Design views with Razor syntax
• Add client-side validation and styling
• Configure routing and dependency injection
• Test functionality and error handling

1. Project Setup

• Create ASP.NET Core MVC project
• Install necessary NuGet packages (Entity Framework, etc.)
• Configure appsettings.json with connection strings

2. Database Layer

• Create DbContext class
• Define entity models with proper relationships
• Configure Entity Framework migrations
• Seed initial data

3. Controller Implementation

• Implement CRUD operations
• Add input validation and error handling
• Use async/await for database operations
• Implement proper HTTP status codes

4. View Development

• Create strongly-typed views
• Implement responsive layouts
• Add client-side validation with jQuery
• Use partial views for reusable components

5. Frontend Integration

• Configure CSS frameworks (Bootstrap)
• Implement JavaScript functionality
• Add AJAX calls for dynamic updates
• Optimize for mobile responsiveness

Example 1: Complete CRUD Controller Input: Need user management functionality Output:

CSHARP
public class UserController : Controller
{
    public async Task<IActionResult> Index()
    {
        return View(await _context.Users.ToListAsync());
    }
    
    public IActionResult Create() => View();
    
    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Create([Bind("Name,Email")] User user)
    {
        if (ModelState.IsValid)
        {
            _context.Add(user);
            await _context.SaveChangesAsync();
            return RedirectToAction(nameof(Index));
        }
        return View(user);
    }
    
    public async Task<IActionResult> Edit(int? id)
    {
        if (id == null) return NotFound();
        var user = await _context.Users.FindAsync(id);
        return user == null ? NotFound() : View(user);
    }
}

Example 2: Razor View with Form Input: Create product entry form Output:

HTML
@model Product

<form asp-action="Create" method="post">
    <div class="form-group">
        <label asp-for="Name" class="control-label"></label>
        <input asp-for="Name" class="form-control" />
        <span asp-validation-for="Name" class="text-danger"></span>
    </div>
    <div class="form-group">
        <label asp-for="Price" class="control-label"></label>
        <input asp-for="Price" class="form-control" type="number" step="0.01" />
        <span asp-validation-for="Price" class="text-danger"></span>
    </div>
    <button type="submit" class="btn btn-primary">Create</button>
</form>

• Use dependency injection for services and DbContext
• Implement proper error handling with try-catch blocks
• Apply data annotations for validation
• Use async/await for all database operations
• Follow naming conventions (PascalCase for public members)
• Implement proper security (ValidateAntiForgeryToken, authorization)
• Use strongly-typed views and avoid ViewBag when possible
• Implement proper logging throughout the application
• Keep controllers thin, move business logic to services
• Use Entity Framework migrations for database changes

• Don't expose DbContext directly in views
• Don't ignore ModelState validation in POST actions
• Don't forget to dispose of resources (use using statements)
• Don't mix synchronous and asynchronous code
• Don't return sensitive data in JSON responses
• Don't forget Cross-Site Request Forgery (CSRF) protection
• Don't use string concatenation for SQL queries (use LINQ/EF)
• Don't forget to handle null reference exceptions
• Don't put business logic in controllers
• Don't forget to implement proper error pages (404, 500)