.Net Core訪問https接口報錯：The requested security protocol is not supported

需要在設置協議類型前需要先設置協議版本信息，如下：

HttpWebRequestreq = (HttpWebRequest)HttpWebRequest.Create(url);

ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
//設置協議類型前設置協議版本
req.ProtocolVersion = HttpVersion.Version11;
//這里設置了協議類型。
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
 ServicePointManager.CheckCertificateRevocationList = true;
ServicePointManager.DefaultConnectionLimit = 1000;
ServicePointManager.Expect100Continue = false;

 

public bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{
    return true;
}