Aspect-oriented programming (AOP) is a paradigm that allows developers to isolate cross-cutting concerns from the core business logic of an application. Cross-cutting concerns like logging, authentication, and error handling typically span multiple layers or modules, making the code harder to maintain and less modular. With AOP, these concerns are handled in separate modules, known as “aspects,” which can be applied wherever needed in the application. This leads to cleaner code, enhanced maintainability, and a reduction in common coding errors. For more details on AOP and its benefits, you can refer to my previous article on the topic.
In this article, we explore how to implement AOP in C# using the DispatchProxy class. Unlike other libraries like PostSharp or frameworks like Autofac, DispatchProxy provides a native, lightweight way to intercept method calls and inject logic without the need for external dependencies. To follow along with the code examples, you’ll need Visual Studio 2022 Preview installed on your machine, which you can download from the official website if you haven’t already done so.
To begin, we need to set up a .NET Core 9 console application in Visual Studio 2022 Preview. If you’re ready, follow these steps to create a new project:
- Open Visual Studio 2022 and click on “Create new project.”
- In the “Create new project” window, select the “Console App (.NET Core)” template.
- Click Next and choose a project name and location.
- In the “Additional Information” window, select “.NET 9.0 (Preview)” as your target framework.
- Click Create to set up the project.
Once you’ve created your .NET 9 console application, we can begin implementing the core AOP functionality using DispatchProxy.
Cross-cutting concerns are the bane of many developers, as they often result in duplicated code and hinder the modularity of an application. Common examples of such concerns include logging, performance monitoring, and security authentication. These elements need to be consistently applied across multiple layers of an application, leading to repetitive code that complicates maintenance. AOP is an effective way to resolve these issues by isolating these concerns in separate modules, allowing developers to focus on the core business logic while seamlessly applying cross-cutting functionality. This approach not only improves the readability of the code but also enhances its flexibility, making it easier to evolve over time.