Customizing ASP.NET Core 5.0

Turn the right screws in ASP.NET Core to get the most out of the framework

Jürgen Gutsch

• Publisher: Packt Publishing
• Year: 2021
• Print ISBN: 9781801077866
• eBook ISBN: 9781801079303
• Edition: 1
• Topic: Computer Science
• Subtopic: Programming in C#
• Index: Computer Science

A guide to discovering the hidden behaviors of ASP.NET Core that can be customized to optimize your.NET 5 applications

Key Features

• Customize the default behavior of ASP.NET Core to get the most out of the framework
• Enhance the app configuration, change the default dependency injection, and build your own tag helpers
• Discover best practices for configuring ASP.NET Core, from user interface design to hosting it on platforms

Book Description

ASP.NET Core is the most powerful Microsoft web framework. Although it's full of rich features, sometimes the default configurations can be a bottleneck and need to be customized to suit the nature and scale of your app. If you're an intermediate-level.NET developer who wants to extend.NET Core to multiple use cases, it's important to customize these features so that the framework works for you effectively.

Customizing ASP.NET Core 5.0 covers core features that can be customized for developing optimized apps. The customization techniques are also updated to work with the latest.NET 5 framework.

You'll learn essential concepts relating to optimizing the framework such as configuration, dependency injection, routing, action filters, and more. As you progress, you'll be able to create custom solutions that meet the needs of your use case with ASP.NET Core. Later chapters will cover expert techniques and best practices for using the framework for your app development needs, from UI design to hosting. Finally, you'll focus on the new endpoint routing in ASP.NET Core to build custom endpoints and add third-party endpoints to your web apps for processing requests faster.

By the end of this application development book, you'll have the skills you need to be able to customize ASP.NET Core to develop robust optimized apps.

What you will learn

• Explore various application configurations and providers in ASP.NET Core 5
• Understand dependency injection in.NET and learn how to add third-party DI containers
• Discover the concept of middleware and write your own middleware for ASP.NET Core apps
• Create various API output formats in your API-driven projects
• Get familiar with different hosting models for your ASP.NET Core app
• Develop custom routing endpoints and add third-party endpoints
• Configure WebHostBuilder effectively for your web applications

Who this book is for

This.NET 5 book is for.NET developers who need to change the default behaviors of the framework to help improve the performance of their applications. Intermediate-level knowledge of ASP.NET Core and C# is required before getting started with the book.

Chapter 1: Customizing Logging

In this first chapter of the book about customizing ASP.NET Core, you will see how to customize logging. The default logging only writes to the console or to the debug window. This is quite good for the majority of cases, but it may be the case that you need to log to a sink, such as a file or a database. Perhaps you want to extend the logger with additional information. In these cases, you need to know how to change the default logging.

In this chapter, we will be covering the following topics:

• Configuring logging
• Creating a custom logger
• Plugging in an existing third-party logger provider

The topics in this chapter refer to the hosting layer of the ASP.NET Core architecture:

Figure 1.1 – ASP.NET Core architecture

Technical requirements

To follow the descriptions in this chapter, you will need to create an ASP.NET Core MVC application. Open your console, shell, or bash terminal, and change to your working directory. Use the following command to create a new MVC application:

dotnet new mvc -n LoggingSample -o LoggingSample

Now, open the project in Visual Studio by double-clicking the project file or, in VS Code, by typing the following command in the already open console:

cd LoggingSample

code.

All of the code samples in this chapter can be found in the GitHub repository for this book at https://github.com/PacktPublishing/Customizing-ASP.NET-Core-5.0/tree/main/Chapter01.

Configuring logging

In previous versions of ASP.NET Core (pre-2.0), logging was configured in Startup.cs. As a reminder, since version 2.0, the Startup.cs file has been simplified, and a lot of configurations were moved to default WebHostBuilder, which is called in Program.cs. Also, logging was moved to default WebHostBuilder.

In ASP.NET Core 3.1 and later versions, the Program.cs file gets more generic, and IHostBuilder will be created first. IHostBuilder is pretty useful for bootstrapping an application without all the ASP.NET web stuff. We'll learn a lot more about IHostBuilder later on in the following chapters. With this IHostBuilder, we create IWebHostBuilder to configure ASP.NET Core. In ASP.NET Core 3.1 and later versions, we get IWebHostBuilder with the webBuilder variable:

public class Program

{

public static void Main(string[] args)

{

CreateHostBuilder(args).Build().Run();

}

public static IHostBuilder CreateHostBuilder(string[]

args) =>

Host.CreateDefaultBuilder(args)

.ConfigureWebHostDefaults(webBuilder =>

{

webBuilder.UseStartup<Startup>();

});

}

In ASP.NET Core, you are able to override and customize almost everything. This includes logging. ...

Table of contents

• Customizing ASP.NET Core 5.0
• Why subscribe?
• Preface
• Chapter 1: Customizing Logging
• Chapter 2: Customizing App Configuration
• Chapter 3: Customizing Dependency Injection
• Chapter 4: Configuring and Customizing HTTPS with Kestrel
• Chapter 5: Using IHostedService and BackgroundService
• Chapter 6: Writing Custom Middleware
• Chapter 7: Content Negotiation Using a Custom OutputFormatter
• Chapter 8: Managing Inputs with Custom ModelBinders
• Chapter 9: Creating a Custom ActionFilter
• Chapter 10: Creating Custom TagHelpers
• Chapter 11: Configuring WebHostBuilder
• Chapter 12: Using Different Hosting Models
• Chapter 13: Working with Endpoint Routing
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