c# - 连接尝试失败，因为连接方在一段时间后没有正确响应，或者建立连接失败

Question

我有一个问题:

A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond URL.

我也遇到这样的问题:

System.IO.IOException: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host

和

System.Net.WebException: The operation has timed out at System.Net.WebClient.UploadFile(Uri address, String method, String fileName)

我知道以前有人问过这个问题，但请相信我，我最后尝试了几乎每一个解决方案。

奇怪的是这个问题根本没有出现在我这边，只有当客户端尝试使用不是常量的时候才会出现。有时我的应用程序在他们端也能正常工作。

我想要完成的是我创建了一个桌面应用程序(Win Forms 和 C#)并尝试登录客户端，同时向托管在 GODaddy 上的我的 php api 服务器发送请求。

var request = (HttpWebRequest)WebRequest.Create("url");
if (request != null)
{
    #region System.Net.WebException
    request.Method = "POST";
    if (!string.IsNullOrEmpty(body))
    {
        var requestBody = Encoding.UTF8.GetBytes(body);
        request.ContentLength = requestBody.Length;
        request.ContentType = "application/json";
        using (var requestStream = request.GetRequestStream())
        {
            requestStream.Write(requestBody, 0, requestBody.Length);
        }
    }
    else
    {
        request.ContentLength = 0;
    }
    request.Timeout = 15000;
    request.CachePolicy = new RequestCachePolicy(RequestCacheLevel.BypassCache);

    string output = string.Empty;
    try
    {
        using (var response = (HttpWebResponse)request.GetResponse())
        {
            using (var stream = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(1252)))
            {
                if (response.StatusCode == HttpStatusCode.OK)
                {
                    while (!stream.EndOfStream)
                    {
                        output += stream.ReadLine();
                    }
                    output = stream.ReadToEnd();
                }
            }
        }
    }
    catch
    {
        // Excaption Caught here
    }
}

请帮帮我。

提前致谢。

Answer 1

尝试添加这个...

request.KeepAlive = false;
request.ProtocolVersion = HttpVersion.Version10;
request.ServicePoint.ConnectionLimit = 12;

MSDN 文章建议每个 CPU 12 个连接，因此限制为 12 个，因为它由 GoDaddy 托管，所以我确信服务器资源是有限的。