.NET Core: HttpClientFactory: How to configure ConfigurePrimaryHttpMessageHandler without dependency injection?

Question

I have a .NET Core class library. Am creating HttpClient instance using IHttpClientFactory without dependency injection. I have included Microsoft DI nuget package in my class library.

Sample Code #1:

Class A {

private readonly HttpClient client;

 public A(){
            var serviceProvider = new ServiceCollection().AddHttpClient().BuildServiceProvider();
            var _httpClientFactory = serviceProvider.GetService<IHttpClientFactory>();
            client = _httpClientFactory.CreateClient();  //HttpClient instance created
            //TODO: Add custom message handler without DI.
  }
}

Using DI, we can configure custom message handlers: Sample code #2 with DI:

services.AddHttpClient()
        .ConfigurePrimaryHttpMessageHandler(() =>
        {
            return new HttpClientHandler
            {
                ServerCertificateCustomValidationCallback = (m, crt, chn, e) => true
            };
        });

I want to add HttpClientHandler to my Sample code #1 without DI. How to configure primary message handler without DI?

Answer 1

I think it's a weird setup that you have, but apart from that, you can probably do something like this:

private readonly HttpClient client;

public A() {
    var serviceProvider = new ServiceCollection()
        .AddHttpClient("YourHttpClientName")
        .Configure<HttpClientFactoryOptions>("YourHttpClientName", options =>
            options.HttpMessageHandlerBuilderActions.Add(builder =>
                builder.PrimaryHandler = new HttpClientHandler
                {
                    ServerCertificateCustomValidationCallback = (m, crt, chn, e) => true
                }))
        .BuildServiceProvider();
    var _httpClientFactory = serviceProvider.GetService<IHttpClientFactory>();
    client = _httpClientFactory.CreateClient();  //HttpClient instance created
    //TODO: Add custom message handler without DI.
}

I just checked the implementation of ConfigurePrimaryHttpMessageHandler and chained it into your setup.

---

My suggestion would be to change your code and properly use DI, as .NET Core heavily relies on this.