ASP.NET is one of the most successful web application development frameworks by Microsoft. With every update, new and extended features are added which in turn help developers in deploying highly scalable and high-performance web applications. Within the framework itself, there are several features that helps in overcoming common development challenges and problems and as well assist doing more with your apps, and boost overall performance.

The following highlights some of the important features that will help you to build better applications using ASP.NET Core

1. Cross-Platform & Container Support

With the introduction of .NET Core 2.x and above, you can now create ASP.NET applications and deploy them to Windows, Linux, and macOS. Microsoft and the community have put a huge effort into making ASP.NET cross platform.

Also, Containers are becoming prevalent in the world of clouds these days. Docker, Kubernetes and other technologies are all gaining more and more popularity. ASP.NET Core allows developers to utilize all of these new awesome technologies. Microsoft Azure even has support for deploying your application to containers and Kubernetes.

2. High performance

In Modern application software development, performance is always a very critical feature. With the introduction of ASP.NET Core and the Kestrel web server, ASP.NET is touted as one of the fastest web application frameworks available. 

The technology that powered the ASP.NET integrated pipeline and IIS is also 15 years old. It did everything and carried a lot of baggage with it. The new Kestrel web server  was redesigned from scratch to take advantage of asynchronous programming models, hence, it is much more lightweight, and extremely fast!

See Comparison between Kestrel Webserver and IIS

3. Asynchronous with the async/await keywords

ASP.NET has excellent support for the utilization of  asynchronous programming patterns. Async is now implemented in all common .NET Framework classes and most third-party libraries. Most modern applications spend most of their time and CPU cycles waiting for database queries, web service calls, and other I/O operations to complete.

One of the reasons ASP.NET Core is extremely fast is its extensive use of asynchronous patterns within the new MVC and Kestrel frameworks.

4. MVC & Web API frameworks Merging

Before ASP.NET Core, developers were most commonly using the MVC and Web API frameworks. MVC was tailored to only create web applications that served up HTML. In contrast to this, Web API was designed to create RESTful services using JSON or XML.

With ASP.NET Core, MVC and Web API becoming merged together. Now, MVC can now return JSON data instead of just HTML only. This Merging was a good move that helped in simplifying development process.

ASP.NET Core also have the new Razor Pages. They extend the MVC framework to allow encapsulating the controller and model aspects of a page together with a two-way binding. This can be seen as a sort of a replacement for WebForms while using the familiar Razor syntax and a code behind.

5. Multiple environments and development mode

This is actually one of my favorite features. This environment feature allows a developer to easily differentiate parts of your code for their behavior in development, staging or production, etc. There was no standard way to do this before the invention of ASP.NET Core.

Environments are perfect for using different CSS or Javascript files. Personally, I use CDN in production, but local files during development. See the code sample below for more information.

6. Dependency Injection

One of the great inbuilt new features of ASP.NET Core is dependency injection. It is heavily used within ASP.NET MVC itself. It is the preferred way of passing things like logging contexts, database contexts, and other things into your MVC controllers.

public class PaymentService: IPaymentService

{

  public ILogger Logger { get; }

  public PaymentService(ILoggerFactory loggerFactory)

  {

    Logger = loggerFactory?.CreateLogger();

    if(Logger == null)

    {

      throw new ArgumentNullException(nameof(loggerFactory));

    }

    Logger.LogInformation("PaymentService created");

  }

}

7. WebSockets & SignalR

ASP.NET has first class support for WebSockets. This can be used to persist long running connections and communicate back and forth with the browser. SignalR is a full framework that is also available which makes it easy to handle common scenarios that requires real time update.

8. Cross-Site Request Forgery (CSRF) Protection

In every web application project, Security is always an important factor that will always be considered. It is also one of those things that can be a lot of work to prevent especially for certain types of attacks. CSRF is used by hackers in hijacking users authenticated session to perform an action that they did not initiate. Like transfer of funds

ASP.NET has a good framework that is available to prevent these types of attacks. it performs this by generating anti-forgery tokens.

9. Action Filters

One of the great features of ASP.NET is the support for filtering. This allows you to implement functionality that can be applied to either an entire controller or to an entire action. Filters are used to specify caching, error handling, authorization, or any custom logic you would like to implement.

using System;

using System.Web.Mvc;

namespace MvcApplication1.Controllers

{
     public class DataController : Controller

     {
          [OutputCache(Duration=10)]

          public string Index()

          {
               return DateTime.Now.ToString("T");

          }
     }
}

10. Extensible Output Caching

This feature allows ASP.NET to cache the output generated by a page on the user’s browser and serve this cached content for future requests. It stores the data that is not updated frequently and outputs that specific data from the browser’s cached location.

Please note that ASP.NET makes it easy to specify how long any request should be cached via common HTTP headers. It also has support for caching output within the memory on your web server itself. You can as well use Redis or other providers to handle your output caching.

11. Swagger OpenAPI

Swagger is very useful if you are creating RESTful API applications. It makes it easy to document and test your APIs.