System.Net.WebException: 操作超时

Question

我有一个复杂的代码，在一个部分中，我向 Web 服务发送了一个其余的 Web 请求，并得到了它对其余工作的响应，响应有不同的大小，有时很重，在 VS 上的 IIS Express 上没有没有任何问题，但是在 IIS 上运行时它会抛出 System.Net.WebException：操作已超时。这是我使用的代码：

  Dim req As HttpWebRequest = TryCast(WebRequest.Create("http://www.somedomain.com/service.svc"), HttpWebRequest)
        Using TryCast(req, IDisposable)
            req.Proxy = Nothing
            req.ServicePoint.ConnectionLimit = 100
            req.ServicePoint.MaxIdleTime = 3000000
            req.Method = "POST"
            req.Headers("Accept-Encoding") = "gzip,deflate"
            req.ContentType = "application/soap+xml; charset=UTF-8"

            If compressionRequested = True Then
                ''  if you want to receive compressed response 

                req.Headers.Add("Accept-Encoding", "gzip, deflate")
            End If
            Dim stOut As New StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII)

            stOut.Write(xml.ToString)
            stOut.Close()


            Using resp As HttpWebResponse = DirectCast(req.GetResponse(), HttpWebResponse)
                If resp.ContentEncoding = "gzip" Then


                    Dim st As Stream = resp.GetResponseStream()
                    If resp.ContentEncoding.ToLower().Contains("gzip") Then
                        st = New System.IO.Compression.GZipStream(st, System.IO.Compression.CompressionMode.Decompress)
                    ElseIf resp.ContentEncoding.ToLower().Contains("deflate") Then
                        st = New System.IO.Compression.DeflateStream(st, System.IO.Compression.CompressionMode.Decompress)
                    End If
                    Dim bfst As BufferedStream = New BufferedStream(st)
                    Using stIn As New StreamReader(bfst, Encoding.[Default])
                        respXml = stIn.ReadToEnd()


                        stIn.Close()
                    End Using

                Else
                    Using stIn As New StreamReader(resp.GetResponseStream())
                        respXml = stIn.ReadToEnd()

                        stIn.Close()
                    End Using
                End If
            End Using

        End Using

也在 web.config 我配置了这个：

<system.net>
<connectionManagement>
        <add address="*" maxconnection="100" />
        </connectionManagement>
    <settings>
      <servicePointManager expect100Continue="true" />
    </settings>
  </system.net>

请问问题出在哪里，如何解决？

Answer 1

通过在此代码之前添加一个 GC.Collect()，一切正常，

System.Net.WebException: 操作超时

System.Net.WebException: The operation has timed out

asp.net

vb.net

httpwebrequest

httpwebresponse

system.net.webexception