ASP.NET Core Overview

What is ASP.NET Core?

ASP.NET Core is a free, open-source, cross-platform framework for building modern, cloud-based, internet-connected applications. It's a complete rewrite of the ASP.NET platform, designed for high performance, modularity, and extensibility.

Key benefits and characteristics include:

  • Unified Programming Model: Provides a single programming model for building web applications, microservices, mobile backends, and more.
  • Cross-Platform: Runs on Windows, macOS, and Linux.
  • Cross-Platform Development: Can be developed on Windows, macOS, or Linux using popular IDEs like Visual Studio, Visual Studio Code, or JetBrains Rider.
  • Cloud-Ready: Designed for deployment to on-premises servers or the cloud, such as Azure.
  • Open-Source: Developed openly with community participation on GitHub.
  • High Performance: Optimized for speed and scalability.

Cross-Platform Development

One of the most significant advantages of ASP.NET Core is its ability to run and be developed on multiple operating systems. This flexibility allows developers to choose their preferred development environment and deploy applications to a wide range of hosting platforms.

High Performance

ASP.NET Core has been engineered from the ground up for performance. By minimizing overhead, optimizing memory management, and leveraging modern C# features, it achieves remarkable speed, often outperforming other popular web frameworks.

Modern Web Development

The framework embraces modern development paradigms, including microservices architecture, single-page applications (SPAs), and API-first development. It integrates seamlessly with popular JavaScript frameworks like React, Angular, and Vue.js.

Key Features

ASP.NET Core offers a rich set of features designed to simplify and accelerate web development:

Middleware

ASP.NET Core uses a pipeline of middleware components to handle HTTP requests. Each component can process the request and pass it to the next component in the pipeline, or it can terminate the request early. This modular approach makes it easy to customize the request processing pipeline.


using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
}

app.UseRouting();

app.UseEndpoints(endpoints =>
{
    endpoints.MapGet("/", async context =>
    {
        await context.Response.WriteAsync("Hello, World!");
    });
});

app.Run();

Dependency Injection (DI)

Built-in support for dependency injection makes it easier to manage dependencies, write loosely coupled code, and improve testability. Services can be registered and resolved directly from the framework.

Routing

ASP.NET Core's routing system maps incoming HTTP requests to specific actions or endpoints within your application. It supports conventional routing, attribute routing, and Razor Pages routing.

Configuration

A flexible configuration system allows you to load settings from various sources, including JSON files, environment variables, command-line arguments, and Azure Key Vault. This makes it easy to adapt your application to different deployment environments.

Logging

A built-in logging abstraction provides a unified API for logging events from your application and the framework itself. It supports multiple logging providers, such as Console, Debug, Event Log, and Azure Application Insights.

Typical Project Structure

An ASP.NET Core web application typically has a structured layout that promotes organization and maintainability. This includes folders for controllers, views, models, services, and configuration files.

  • Pages/ (for Razor Pages)
  • Controllers/ (for MVC Controllers)
  • Models/ (for application data models)
  • wwwroot/ (for static assets like CSS, JavaScript, and images)
  • appsettings.json (for configuration)
  • Program.cs (entry point of the application)

Getting Started

To start building with ASP.NET Core, you'll need to install the .NET SDK. You can then create new projects using the .NET CLI:


dotnet new webapp -o MyWebApp
cd MyWebApp
dotnet run

This will create a new Razor Pages web application and run it locally, making it accessible via `https://localhost:5001` (or a similar port).