使用HttpWebRequest进行请求时发生错误：基础连接已关闭，发送时发生错误处理

最近调试原来的微信模拟登陆时发生了“基础连接已关闭，发送时发生错误”的错误提示，原来都是好好的，只是很久没用了。

出错代码如下：

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("https://mp.weixin.qq.com/cgi-bin/loginpage?t=wxm2-login&lang=zh_CN");///cgi-bin/loginpage?t=wxm2-login&lang=zh_CN
            req.CookieContainer = cookie;
            req.Method = "GET";
            req.ProtocolVersion = HttpVersion.Version10;
            HttpWebResponse res = (HttpWebResponse)req.GetResponse();
            StreamReader rd = new StreamReader(res.GetResponseStream());
            string theContent = rd.ReadToEnd();

经过一番Google和试验，答案既如此简单，增加如下一句：

            ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
通过代码如下：

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("https://mp.weixin.qq.com/cgi-bin/loginpage?t=wxm2-login&lang=zh_CN");///cgi-bin/loginpage?t=wxm2-login&lang=zh_CN           

req.CookieContainer = cookie;
            req.Method = "GET";
            req.ProtocolVersion = HttpVersion.Version10;
           ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
            HttpWebResponse res = (HttpWebResponse)req.GetResponse();
            StreamReader rd = new StreamReader(res.GetResponseStream());
            string theContent = rd.ReadToEnd();

记录一下，以防后错！