Question

我的VB.Net应用程序出了问题。当我试图在没有代理的情况下向http://ask.fm发送请求时，我在fiddler中得到以下响应：HTTP / 1.1 502 Fiddler - DNS查找失败

这是什么意思？为什么在为请求使用代理服务器时没有错误？

我使用以下代码发送请求：

  Public Function GetRequest(ByVal url As String, ByVal referer As String, ByVal cookie As CookieContainer, Optional proxy As String = "") As String

    Dim request As HttpWebRequest
    Dim response As HttpWebResponse

    Try
        Dim cookies As String = ""
        request = CType(HttpWebRequest.Create(url), HttpWebRequest)
        request.CookieContainer = cookie
        request.ServicePoint.Expect100Continue = False
        request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:8.0) Gecko/20100101 Firefox/8.0"
        If referer <> "" Then
            request.Referer = referer
        End If
        request.Timeout = 10000
        If proxy <> "" Then
            request.Proxy = New WebProxy(proxy)
        End If
        response = CType(request.GetResponse(), HttpWebResponse)

        cookies = response.GetResponseHeader("Set-Cookie")

        If url.Contains("ask.fm/") Then
            If New Regex("l=.*?; domain=ask.fm; path=/;").Match(cookies).Value = "" Then
                Return "ERROR"
            End If
        End If

        Dim source As String = New StreamReader(response.GetResponseStream()).ReadToEnd()
        If source.Contains("No robots allowed!") Then
            source = "ERROR"
        End If
        If source = "" Then
            source = "ERROR"
        End If
        Return source
    Catch ex As Exception
        Return "ERROR"
    End Try

End Function

Answer 1

您是否正在使用 Fiddler 来检查流量？如果是这样，请确保Fiddler可以正确地重定向您的流量。

转到帮助＆gt;关于Fiddler 并确保您的网关正确（如果您可以直接访问，则设置为您用于访问互联网的代理或等于无网关）。

使用无代理时请求出错

1 个答案: