微信退款时候报”请求被中止: 未能创建 SSL/TLS 安全通道“或”The request was aborted: Could not create SSL/TLS secure channel“的错误

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12 | SecurityProtocolType.Ssl3;
ServicePointManager.DefaultConnectionLimit = 9999;

ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);

public static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{
    //直接确认，否则打不开    
 　　return true;
}