System.Net.WebException: 'The underlying connection was closed: An unexpected error occurred on a receive.'

Question

有人可以帮我写下面的代码吗？我有一个功能，我试图使用 URL "https://www1.nseindia.com/live_market/dynaContent/live_analysis/pre_open/all.json".

从网站获取一些数据

但出于某种原因，我总是收到 System.Net.WebException“'The underlying connection was closed: An unexpected error occurred on a receive.'”

我也可以使用 URL“https://www.nseindia.com/api/market-data-pre-open?key=ALL”获得相同的数据，但在这里我再次使用 C#.net 代码时得到相同的 WebException。

以下是我的代码：

public static string GetNSEData()
        {
            //*********get the json file using httpRequest ***********
            HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create("https://www1.nseindia.com/live_market/dynaContent/live_analysis/pre_open/all.json");
            httpWebRequest.Method = WebRequestMethods.Http.Get;
            httpWebRequest.Accept = "application/json; charset=utf-8";
            httpWebRequest.UserAgent = @"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36";
            //ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
            //ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;

            string file;
            var response = (HttpWebResponse)httpWebRequest.GetResponse();
            using (var sr = new StreamReader(response.GetResponseStream()))
            {
                file = sr.ReadToEnd();
            }
            return file;
        }

我尝试了 HTTPWebRequest 的不同变体以及不同的参数，但没有成功。在每种情况下，我要么得到相同的异常，要么 "The remote server returned an error: (403) Forbidden."

以下是我尝试过的选项：

System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a receive

非常感谢任何帮助...

Answer 1

您只需要摆脱 httpWebRequest.UserAgent 然后一切似乎都工作正常，因为 Http 请求不需要它。

public static string GetNSEData()
    {

        HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create("https://www1.nseindia.com/live_market/dynaContent/live_analysis/pre_open/all.json");
        httpWebRequest.Method = WebRequestMethods.Http.Get;
        httpWebRequest.Accept = "application/json; charset=utf-8";

        string file;
        var response = (HttpWebResponse)httpWebRequest.GetResponse();
        using (var sr = new StreamReader(response.GetResponseStream()))
        {
            file = sr.ReadToEnd();
        }
        return file;
    }

System.Net.WebException: 'The underlying connection was closed: An unexpected error occurred on a receive.'

System.Net.WebException: 'The underlying connection was closed: An unexpected error occurred on a receive.'

c#

httpwebrequest

system.net.webexception