C# HttpClient 代理接入示例

using System.Net;

var proxyHost = Environment.GetEnvironmentVariable("PROXY_HOST")
    ?? throw new InvalidOperationException("Missing PROXY_HOST");
var proxyPort = Environment.GetEnvironmentVariable("PROXY_PORT")
    ?? throw new InvalidOperationException("Missing PROXY_PORT");
var proxyUsername = Environment.GetEnvironmentVariable("PROXY_USERNAME")
    ?? throw new InvalidOperationException("Missing PROXY_USERNAME");
var proxyPassword = Environment.GetEnvironmentVariable("PROXY_PASSWORD")
    ?? throw new InvalidOperationException("Missing PROXY_PASSWORD");

var proxy = new WebProxy(new Uri($"http://{proxyHost}:{proxyPort}"))
{
    Credentials = new NetworkCredential(proxyUsername, proxyPassword),
};
using var handler = new HttpClientHandler
{
    Proxy = proxy,
    UseProxy = true,
};
using var client = new HttpClient(handler)
{
    Timeout = TimeSpan.FromSeconds(30),
};

using var response = await client.GetAsync("https://<public-test-host>/ip");
response.EnsureSuccessStatusCode();
Console.WriteLine(await response.Content.ReadAsStringAsync());