C# httpwebrequest 访问错误---Message: System.Net.WebException : The underlying connection was closed

错误内容：

Message: System.Net.WebException : The underlying connection was closed: An unexpected error occurred on a send.
---- System.IO.IOException : Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
-------- System.Net.Sockets.SocketException : An existing connection was forcibly closed by the remote host

 

解决方案：

在HttpWebRequest request = WebRequest.Create(serviceUrl) as HttpWebRequest;之前加下面这句code：

ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

我试了好多修复的方法都不行，最后问到万能的同事解决了，哈哈，是很给力没错了。

扒拉好多的资料其中之一如下：

https://briancaos.wordpress.com/2012/06/15/an-existing-connection-was-forcibly-closed-by-the-remote-host/

这个链接中的方法对我没效果，但是大家也可以参考，我看有很多人用这个方法也解决了。下班喽！