c# - 如何在 dotnet 核心中为 HttpClient 指定 HTTP/2 "prior knowledge"模式？

Question

使用 dotnet Core 3.1，以下服务器接受 HTTP/2 请求:

using System;
using System.Threading.Tasks;
using System.Net.Http;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore;
using System.Threading;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Server.Kestrel.Core;

namespace http2
{
    class Program
    {
        static void Main(string[] args)
        {
            CreateWebHostBuilder(args).Build().Run();
        }

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .ConfigureKestrel((context, serverOptions) =>
                {
                    serverOptions.ListenLocalhost(8080, listenOptions =>
                    {
                        listenOptions.Protocols = HttpProtocols.Http2; // this line is important
                    });
                });
    }

    class Startup
    {
        public void Configure(IApplicationBuilder app)
        {
            app.Run(context => ProcessAsync(context));
        }

        internal async Task<bool> ProcessAsync(HttpContext context)
        {
            await context.Response.WriteAsync("This is the response: toto");
            return true;
        }
    }
}

例如，如果您尝试以下操作，您会得到响应:curl --silent --http2-prior-knowledge http://localhost:8080

我的问题是关于如何实际执行 curl 正在执行的操作？但在 C# 中。

我试过:

static void ClientCode(object parameter)
{
      SocketsHttpHandler handler = new SocketsHttpHandler();
      using (var client = new HttpClient(handler))
      {
           var request = new HttpRequestMessage(HttpMethod.Get, "http://localhost:8080");
           request.Version = new Version(2, 0);

           var response = client.SendAsync(request).Result;
           if (response.IsSuccessStatusCode)
           {
                var s = response.Content.ReadAsStringAsync().Result;
                Console.WriteLine(s);
           }
      }
}

但我只是得到一个异常(exception)。

是否可以使用 prior knowledge mode在 C# 和 dotnet Core 中使用 HttpClient？

Answer 1

我在 net5.0 上，只有在显式设置 VersionPolicy 时才能让它工作

var request = new HttpRequestMessage(HttpMethod.Get, "http://localhost:5001/test");
request.Version = new Version(2, 0);
request.VersionPolicy = HttpVersionPolicy.RequestVersionExact;