访问https接口报错 基础连接已经关闭: 未能为 SSL/TLS 安全通道建立信任关系

在网上查阅了资料找到了解决方案，大致如下

调用http访问前加上这句话

ServicePointManager.CertificatePolicy = new AcceptAllCertificatePolicy();  

internal class AcceptAllCertificatePolicy : ICertificatePolicy
    {
        public AcceptAllCertificatePolicy()
        {
        }

        public bool CheckValidationResult(ServicePoint sPoint,
           X509Certificate cert, WebRequest wRequest, int certProb)
        {
            // Always accept
            return true;
        }
    }

这么写有点麻烦，但是能解决问题

查看了ServerCertificateValidationCallback属性，发现它的类型为RemoteCertificateValidationCallback的委托，为何不直接写一个参数相同的方法直接返回true呢

public delegate bool RemoteCertificateValidationCallback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors);

解决方案

ServicePointManager.ServerCertificateValidationCallback = Callback;

        private static bool Callback(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
        {
            return true;
        }