因为.net core 的System.Net 中没有提供WebProxy这个方法,所以可以根据需求实现一个.

    public class CoreWebProxy : IWebProxy
    {
        public readonly Uri Uri;
        private readonly bool bypass;

        public CoreWebProxy(Uri uri, ICredentials credentials = null, bool bypass = false)
        {
            Uri = uri;
            this.bypass = bypass;
            Credentials = credentials;
        }

        public ICredentials Credentials { get; set; }

        public Uri GetProxy(Uri destination) => Uri;

        public bool IsBypassed(Uri host) => bypass;

        public override int GetHashCode()
        {
            if (Uri == null)
            {
                return -1;
            }

            return Uri.GetHashCode();
        }
    }

参考:
– Specify proxy in asp.net core rc2
– .Net Core中使用Proxy请求数据