将 httpHandler 附加到 httpclientFactory webapi aspnetcore 2.1

Question

我正在尝试使用 "ConfigurePrimaryHttpMessageHandler"

将处理程序附加到 httpclientfactory

但是当我查看 HttpClient 内部时 如果处理程序在那里我找不到它

我是否正确附加了处理程序？

任何建议

     services.AddHttpClient<IGitHubClient,GitHubClient>(client =>
            {
                client.BaseAddress = new Uri(myUri);
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            })
            .ConfigurePrimaryHttpMessageHandler(() => new HttpClientHandler
            {
                AllowAutoRedirect = false,
                AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip
            });


    public interface IGitHubClient
    {
        Task<string> GetData();
    }

    public class GitHubClient : IGitHubClient
    {
        private readonly HttpClient _client;

        public GitHubClient(HttpClient httpClient)
        {
            _client = httpClient;
        }

        public async Task<string> GetData()
        {
            return await _client.GetStringAsync("/");
        }
    }

    public class ValuesController : Controller
    {
        private readonly IGitHubClient _gitHubClient;;

        public ValuesController(IGitHubClient gitHubClient)
        {
            _gitHubClient = gitHubClient;
        }

        [HttpGet]
        public async Task<ActionResult> Get()
        {
            //my _gitHubClient has no Handler attached!!!

            string result = await _gitHubClient.GetData();
            return Ok(result);
        }
    }

Answer 1

您显示的代码是推荐的方法。

关于_gitHubClient的评论

//my _gitHubClient has no Handler attached!!!

好像是个误会。

_gitHubClient 是您的抽象，它在其 GitHubClient 实现中包装了一个 HttpClient 实例。

public class GitHubClient : IGitHubClient {
    private readonly HttpClient _client; //<< Handler will be attached to this instance

    public GitHubClient(HttpClient httpClient) {
        _client = httpClient;
    }

    public async Task<string> GetData() {
        return await _client.GetStringAsync("/");
    }
}

它是具有附加处理程序的包装实例。

根据当前配置，每当框架必须创建 IGitHubClient 派生 GitHubClient 的实例进行注入时，工厂将使用提供的设置创建 HttpClient启动。其中还包括添加 ConfigurePrimaryHttpMessageHandler

提供的 HttpClientHandler