.net 4.0 解决方式
ServicePointManager.SecurityProtocol = (SecurityProtocolType)768 | (SecurityProtocolType)3072;.net 4.5解决方式
System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
以上代码可添加至通信调用之前，或进程启动初始化时