为什么 HttpWebRequest 在第三次或更多次调用时超时？

Question

我需要检查一个 url 是否存在，然后是我的代码：

   private bool CheckConnection(String URL)
    {
        try
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
            request.UseDefaultCredentials = true;
            request.KeepAlive = false;
            request.Timeout = 5000;
            request.ReadWriteTimeout = 5000;
            request.ServicePoint.ConnectionLeaseTimeout = 5000;
            request.ServicePoint.MaxIdleTime = 5000;
            bool bReturn = false;
            using (var response = (HttpWebResponse)request.GetResponse())
            {
                bReturn = (response.StatusCode == HttpStatusCode.OK);
            }
            request.Abort();

        return bReturn;
        }
        catch
        {
            return false;
        }
    }

我在第三次通话时收到消息“超时”，我搜索并修复但无法成功。 谁能帮帮我？

谢谢大家

Answer 1

我一直在努力解决同样的问题，经过一些研发后，我通过在循环中断言响应代码后关闭 HttpResponse 对象进行了故障排除：response.Close();

我的代码：

HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();
int respcode = (int)response.StatusCode;
Assert.IsTrue(respcode == 302 || respcode == 200);
response.Close();

Answer 2

试试下面的代码。一旦我遇到了同样的问题，我就用这个例子修复了它。希望这对你也有用。

  using (var client = new WebClient())
        {
          var values = new NameValueCollection
         {
            { "key", "This is a test that posts this string to a Web server." }
         };
            string url = "http://www.contoso.com/PostAccepter.aspx";
            byte[] result = client.UploadValues(url, values);
            Console.WriteLine(Encoding.UTF8.GetString(result));
        }