Exploring IHttpClientFactory and delegating handlers
IHttpClientFactory is a service that supports creating single or multiple HttpClient instances with custom configuration. We have used the HttpClient instance configured in the previous section with the web API base URL. This was enough to meet our basic needs, but sometimes slightly more advanced techniques are needed to cover the scenarios you may face while developing more complex apps.
In this section, we will learn how to use the HttpClient factory to create and manage HttpClient instances. In addition, we will learn about DelegatingHandlers that allow for building a pipeline to process each HTTP request or response associated with a specific HttpClient instance and when we need such a capability.
To be able to utilize the IHttpClientFactory service, we need to install the Microsoft.Extensions.Http package. You can do that either using the NuGet package manager or through the .NET CLI command:
dotnet add package Microsoft...