HttpClient properties not being passed with DI

I’m working on an ASP.NET Core 5.0 project which has a service that accesses an API. Based on the code below, I’d expect the HttpClient supplied to ToornamentService’s constructor to contain the declared BaseAddress and API key header.

However, when debugging, I noticed that the HttpClient never has either of those. BaseAdress is null, and the header is missing. I’ve tried using an IHttpClientFactory instead of the typed client, but I end up with the same result.

What am I doing wrong?

ConfigureServices Method:

public void ConfigureServices(IServiceCollection services)
    {
        //Omitted for brevity
        services.AddHttpClient<ToornamentService>(c =>
        {
            c.BaseAddress = new Uri("https://api.toornament.com/");
            c.DefaultRequestHeaders.Add("X-Api-Key", Configuration["Toornament:ApiKey"]);
        });

        services.AddTransient<ToornamentService>();
    }

ToornamentService class:

public ToornamentService(HttpClient client)
    {
        Client = client; // client.BaseAddress here is null
    }

Answer

Remove this line: services.AddTransient<ToornamentService>();

When you call AddHttpClient, it injects the service for you as transient.

So what you are doing is injecting it twice. And since your transient injection is the last injection, that takes precedence over the AddHttpClient injection.

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