In the world of software development, every new version of a language or framework often comes with features designed to make developers’ lives easier. With the release of C# 10 and .NET 6, one such feature is Global Using Directives. This seemingly small addition can have a significant impact on the readability and maintainability of your code. In this post, we’ll dive into what global using directives are, how to use them, and the benefits they bring to your C# projects.

What Are Global Using Directives?

Global using directives allow you to declare using directives that are available throughout your entire project. This means you can specify commonly used namespaces once, and they will be automatically included in every file in your project. This feature can drastically reduce the boilerplate code that often clutters the top of your C# files.

How to Use Global Using Directives

Step 1: Create a GlobalUsings.cs File

The first step is to create a file in your project that will contain your global using directives. By convention, this file is often named GlobalUsings.cs, but you can name it anything you like.

Step 2: Define Your Global Usings

In this file, you will define your using directives, prefixed with the global keyword. Here is an example:

// GlobalUsings.cs
global using System;
global using System.Collections.Generic;
global using System.Linq;
global using System.Threading.Tasks;
global using Microsoft.AspNetCore.Builder;
global using Microsoft.Extensions.DependencyInjection;
global using Microsoft.Extensions.Hosting;

Step 3: Enjoy Cleaner Code

With these global using directives in place, you no longer need to include these namespaces at the top of every file in your project. For example, instead of writing this in every file:

using System;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

You can simply rely on the global usings, making your individual files cleaner and more focused on the business logic.

Benefits of Global Using Directives

Reduced Boilerplate

One of the most obvious benefits is the reduction in boilerplate code. By centralizing your common using directives, you avoid the repetitive task of including the same namespaces in multiple files.

Cleaner Code

Your code files become more streamlined and easier to read. With less clutter at the top of each file, developers can focus more on the actual content and functionality of the code.

Consistency

Global using directives ensure that commonly used namespaces are consistently included across your entire project. This reduces the chances of missing a using directive and encountering frustrating compilation errors.

Example in an ASP.NET Core Project

Consider a typical ASP.NET Core project. Without global using directives, each file might start with something like this:

using System;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

With global using directives, you can create a GlobalUsings.cs file:

// GlobalUsings.cs
global using System;
global using Microsoft.AspNetCore.Mvc;
global using Microsoft.Extensions.Logging;

Now, your individual files don’t need to include these using directives:

namespace MyAspNetCoreApp.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public HomeController(ILogger<HomeController> logger)
        {
            _logger = logger;
        }

        public IActionResult Index()
        {
            return View();
        }
    }
}

Practical Tips

  • Use Wisely: While global using directives can reduce redundancy, avoid overusing them. Only include namespaces that are genuinely used across multiple files in your project.
  • Organization: Keep your GlobalUsings.cs file organized and maintainable. As your project grows, you might need to periodically review and update this file to ensure it remains relevant.
  • Avoid Confusion: Be mindful of potential naming conflicts. If different namespaces contain types with the same name, explicitly include the necessary using directive in the relevant file to avoid ambiguity.

Conclusion

Global using directives are a powerful feature in C# 10 and .NET 6 that can help you write cleaner, more maintainable code. By centralizing your using directives, you reduce boilerplate, enhance readability, and ensure consistency across your project. Give them a try in your next C# project and experience the benefits firsthand.

Don’t forget to checkout: C# Basics: Understand the Differences Between Classes, Structs and Records

Categorized in:

.Net,

Last Update: June 20, 2024