如何通过TcpClient获取页面？

Question

我正在尝试通过TCP流向页面发送GET请求.

这是我的代码的样子:

public class SocketLevelWebClient
{
    public string SendWebRequest(string url, string request)
    {
        using(TcpClient tc = new TcpClient())
        {
            tc.Connect(url, 80);

            using (NetworkStream ns = tc.GetStream())
            {
                using (System.IO.StreamWriter sw = new System.IO.StreamWriter(ns))
                {
                    using (System.IO.StreamReader sr = new System.IO.StreamReader(ns))
                    {
                        sw.Write(request);
                        sw.Flush();
                        return sr.ReadToEnd();
                    }
                }
            }
        }
    }

请求本身:

            SocketLevelWebClient wc = new SocketLevelWebClient();
            var r=wc.SendWebRequest("www.youtube.com",@"GET http://www.youtube.com/ HTTP/1.1
Accept: application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, */*
Accept-Language: en-US
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)
Accept-Encoding: gzip, deflate
Connection: Keep-Alive
Host: www.youtube.com"+"\r\n\r\n");

当我调用此代码时,它总是冻结等待来自服务器的响应.

我究竟做错了什么？

Answer 1

问题是ReadToEnd只在流结束时返回.不幸的是,服务器使TCP连接保持活动状态.因此ReadToEnd永远无法检测到真正的结束已经到来.

证明:

                        sw.Write(request);
                        sw.Flush();
                        var l = sr.ReadLine();

l 正在填充请求的第一行.

删除keep-alive标题并添加:

Connection: close

或者使用响应Content-Length头来正确读取它(二进制).