HttpWebRequest-收到“底层连接已关闭”错误

Question

我为这个问题奋斗了2天，我真的受够了。我什么都找不到。

检查以下简单的示例代码：

HttpWebRequest fileReq = (HttpWebRequest)HttpWebRequest.Create(updateInfoFileUrl);
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12; //768 for TLS 1.1 and 3072 for TLS 1.2
ServicePointManager.ServerCertificateValidationCallback = delegate
{
    return true;
};
fileReq.KeepAlive = false;

WebProxy proxy = new WebProxy();
proxy.BypassProxyOnLocal = false;
proxy.UseDefaultCredentials = true;
proxy.Credentials = CredentialCache.DefaultCredentials;
fileReq.Proxy = proxy;

HttpWebResponse fileResp = (HttpWebResponse)fileReq.GetResponse();
Stream stream = fileResp.GetResponseStream();

我尝试了SecurityProtocols的不同组合。只使用一个，全部使用...什么都没有。我尝试了HttpWebRequest，HttpClient甚至XmlDocument.Load。什么都没有。我每次都会得到错误。

这可能是什么问题？

这是我想阅读的文件： https://www.example.com/info.xml

浏览器显示它。甚至PostMan也会显示它。

Answer 1

进行了一些调试。这与您的代码无关，但是服务器需要用户代理设置。 作品：

HttpWebRequest fileReq = (HttpWebRequest)WebRequest.Create(@"https://www.example.com/info.xml");
fileReq.UserAgent = "sadsad";
fileReq.Method = "GET";

HttpWebResponse fileResp = (HttpWebResponse)fileReq.GetResponse();
Stream stream = fileResp.GetResponseStream();

失败：

HttpWebRequest fileReq = (HttpWebRequest)WebRequest.Create(@"https://www.example.com/info.xml");

//     fileReq.UserAgent = "sadsad";
fileReq.Method = "GET";

HttpWebResponse fileResp = (HttpWebResponse)fileReq.GetResponse();
Stream stream = fileResp.GetResponseStream();