网页的状态码

Question

我正在尝试从网页中获取结果，并且为了避免web异常，我想在从流中请求结果之前检查状态代码。但是：

HttpWebResponse response = (HttpWebResponse)webRequest.GetResponse();

当我尝试在此之后使用response.StatusCode获取错误代码时引发异常

有没有一种方法可以避免异常来获取StatusCode

Answer 1

只有在调用了GetResponse()方法之后，才能请求StatusCode。您需要将GetResponse()包装在try/catch块中。看看Check if a url is reachable - Help in optimizing a Class吧。

如果你只是想测试服务器的可达性，那么你可以使用Ping命令。

Answer 2

您可以使用Ping从该站点获取更多统计数据。(虽然有点慢，但需要1-3秒左右)

public string ExecuteCommandSync(object command)
    {
        try
        {
            // create the ProcessStartInfo using "cmd" as the program to be run,
            // and "/c " as the parameters.
            // Incidentally, /c tells cmd that we want it to execute the command that follows,
            // and then exit.
            var procStartInfo = new System.Diagnostics.ProcessStartInfo("cmd", "/c " + command);


            // The following commands are needed to redirect the standard output.
            // This means that it will be redirected to the Process.StandardOutput StreamReader.
            procStartInfo.RedirectStandardOutput = true;
            procStartInfo.UseShellExecute = false;
            // Do not create the black window.
            procStartInfo.CreateNoWindow = true;
            // Now we create a process, assign its ProcessStartInfo and start it
            var proc = new System.Diagnostics.Process();
            proc.StartInfo = procStartInfo;
            proc.Start();

            return proc.StandardOutput.ReadToEnd();
        }
        catch (Exception objException)
        {
            Console.WriteLine("Error: " + objException.Message);
            return "";
            // Log the exception
        }
    }

[发自：C# cmd output in real time Just From changed ]

用法如下：

MessageBox.Show(ExecuteCommandSync("ping www.stackoverflow.com"));