How to Use the Options Pattern in Your Program.cs File in .NET Core

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In this guide, we will explore how to overcome this challenge effectively. Let's dive in!

The Challenge

Here's an example of what you might attempt to do but find it doesn't work as intended:

[[See Video to Reveal this Text or Code Snippet]]

The main issue here is that direct references to configuration settings or options do not work well because the dependency injection (DI) framework hasn't been fully constructed yet by the time you wish to access it.

The Solution

Accessing Configuration After Building the App

Fortunately, there is a solution that allows you to retrieve the configuration settings you need after the application builder setup is complete.

Access the Service Provider: You can access the IServiceProvider once the application has been built.

Retrieve Configuration Using IOptions: Utilize app.Services.GetRequiredService<IOptions<SwaggerConfig>>().Value to get the configured values.

Here's how you can implement this:

[[See Video to Reveal this Text or Code Snippet]]

Breakdown of the Code

Building the App: var app = builder.Build(); builds the app, which also constructs the DI container.

Accessing Configuration: var swaggerConfig = app.Services.GetRequiredService<IOptions<SwaggerConfig>>().Value; retrieves the SwaggerConfig settings, ensuring you can access your configuration properties that were registered earlier.

Using Swagger Configuration: Finally, these configuration values are utilized in setting up Swagger at runtime.

Conclusion

Now that you know how to handle this common issue, take advantage of the Options Pattern to enhance your application settings management. Whether you're working on new features or maintaining existing code, this technique will empower you to build more robust .NET Core applications.

Happy coding!