System.Net.WebException:基础连接已关闭:无法为SSL/TLS安全通道建立信任

一、参考链接

解决基础连接已经关闭
System.Net.WebException

二、处理方式

System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) { return true; };
};
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12 | SecurityProtocolType.Ssl3;
ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
                
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);