为什么使用 WebRequest 发送 post 数据需要这么长时间？

我目前正在创建一个 C# 应用程序来绑定到 php / MySQL 在线系统。应用程序需要将发布数据发送到脚本并获取响应。

当我发送以下数据时

username=test&password;=test  
  

我收到以下回复...

Starting request at 22/04/2010 12:15:42  
Finished creating request : took 00:00:00.0570057  
Transmitting data at 22/04/2010 12:15:42  
Transmitted the data : took 00:00:06.9316931       <<--
Getting the response at 22/04/2010 12:15:49  
Getting response 00:00:00.0360036  
Finished response 00:00:00.0360036  
Entire call took 00:00:07.0247024  
  

正如您所看到的，实际将数据发送到脚本需要 6 秒，我已经通过从 telnet 发送数据以及从本地文件发送 post 数据到 url 进行了进一步的测试，它们甚至不需要一秒钟，所以这是网站上的托管脚本不是问题。

为什么传输两个简单字符串的数据需要 6 秒？

我使用自定义类来发送数据

class httppostdata
{
    WebRequest request;
    WebResponse response;

    public string senddata(string url, string postdata)
    {
        var start = DateTime.Now;
        Console.WriteLine("Starting request at " + start.ToString());

        // create the request to the url passed in the paramaters
        request = (WebRequest)WebRequest.Create(url);


        // set the method to post
        request.Method = "POST";
        // set the content type and the content length
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = postdata.Length;
        // convert the post data into a byte array
        byte[] byteData = Encoding.UTF8.GetBytes(postdata);
        var end1 = DateTime.Now;
        Console.WriteLine("Finished creating request : took " + (end1 - start));

        var start2 = DateTime.Now;
        Console.WriteLine("Transmitting data at " + start2.ToString());
        // get the request stream and write the data to it
        Stream dataStream = request.GetRequestStream();
        dataStream.Write(byteData, 0, byteData.Length);
        dataStream.Close();
        var end2 = DateTime.Now;
        Console.WriteLine("Transmitted the data : took " + (end2 - start2));


        // get the response
        var start3 = DateTime.Now;
        Console.WriteLine("Getting the response at " + start3.ToString());


        response = request.GetResponse();
        //Console.WriteLine(((WebResponse)response).StatusDescription);
        dataStream = response.GetResponseStream();
        StreamReader reader = new StreamReader(dataStream);
        var end3 = DateTime.Now;
        Console.WriteLine("Getting response " + (end3 - start3));

        // read the response
        string serverresponse = reader.ReadToEnd();
        var end3a = DateTime.Now;
        Console.WriteLine("Finished response " + (end3a - start3));

        Console.WriteLine("Entire call took " + (end3a - start));

        //Console.WriteLine(serverresponse);
        reader.Close();
        dataStream.Close();
        response.Close();

        return serverresponse;
    }
}

我用它来称呼它

private void btnLogin_Click(object sender, EventArgs e)
{
    // string postdata;

    if (txtUsername.Text.Length < 3 || txtPassword.Text.Length < 3)
    {
        MessageBox.Show("Missing your username or password.");
    }
    else
    {
        string postdata = "username=" + txtUsername.Text +
                          "&password=" + txtPassword.Text;

        httppostdata myPost = new httppostdata();
        string response = myPost.senddata("http://www.domainname.com/scriptname.php", postdata);
        MessageBox.Show(response);
    }
}

确保将 WebRequest 的代理属性显式设置为 null，否则它将尝试自动检测代理设置，这可能需要一些时间。