c# 中HttpClient访问Https网站

c# 中HttpClient访问Https网站，加入如下代码：

handler = new HttpClientHandler() ;
handler.AllowAutoRedirect = true;
handler.UseCookies = true;
handler.CookieContainer = cookies;

System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;

或者：
handler.ClientCertificateOptions = ClientCertificateOption.Automatic;

httpClient = new HttpClient(handler);