HttpWebRequest提高效率之連接數,代理，自動跳轉,gzip請求等設置問題

先設置4個：

[csharp] 
webrequest.ServicePoint.Expect100Continue = false; 
               //是否使用 Nagle 不使用 提高效率 
               webrequest.ServicePoint.UseNagleAlgorithm = false; 
               //最大連接數 
               webrequest.ServicePoint.ConnectionLimit = 65500; 
               //數據是否緩沖 false 提高效率  
               webrequest.AllowWriteStreamBuffering = false; 

代理的使用：我用的代理都是不要賬號和密碼的，因為要不是免費的，要是是我們自己的，對來訪IP 有限制

[csharp] 
if (proxy!=null) 
               { 
                   model.proxy = proxy; 
                   WebProxy myProxy = new WebProxy(proxy.ProxyInfo, false); 
                   myProxy.Credentials = new NetworkCredential("", ""); 
                   webrequest.Proxy = myProxy; 
               } 
               else 
               { 
                   webrequest.Proxy = GlobalProxySelection.GetEmptyWebProxy(); 
               } 
 

webrequest.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate");

帶上gzip，如果對方支持gzip，流量上可以節省五分之四，原來250KB，用gzip壓縮有 大概在50KB，減少帶寬壓力，增加速度

值得注意的是，如果是gzip，返回值必須要gzip解壓的。

[csharp] 
if (response.ContentEncoding.ToLower().Contains("gzip")) 
                   { 
                       using (GZipStream stream = new GZipStream(response.GetResponseStream(), CompressionMode.Decompress)) 
                       { 
                           using (StreamReader reader = new StreamReader(stream, Encoding.UTF8)) 
                           { 
 
                               model.html = reader.ReadToEnd(); 
                           } 
                       } 
                   } 
 

還有一點：gzip解壓的時候回耗費CPU，所以這個需要注意下

附完成方法

[csharp]
/// <summary> 
       /// Get 方式 獲取數據 
       /// </summary> 
       /// <param name="webUrl"></param> 
       /// <returns></returns> 
       public Model.WebRequestReturnModel WebRequestGetHtmlByGet(string webUrl, CookieContainer cookieContainer, Encoding encoding, string refer,Model.Proxy proxy) 
       { 
           Model.WebRequestReturnModel model = new Model.WebRequestReturnModel(); 
           HttpWebRequest webrequest = null; 
           try 
           { 
               webrequest = WebRequest.Create(webUrl) as HttpWebRequest; 
                
               webrequest.ServicePoint.Expect100Continue = false; 
                webrequest.ServicePoint.UseNagleAlgorithm = false; 
                webrequest.ServicePoint.ConnectionLimit = 65500; 
               webrequest.AllowWriteStreamBuffering = false; 
               if (proxy!=null) 
               { 
                   model.proxy = proxy; 
                   WebProxy myProxy = new WebProxy(proxy.ProxyInfo, false); 
                   myProxy.Credentials = new NetworkCredential("", ""); 
                   webrequest.Proxy = myProxy; 
               } 
               else 
               { 
                   webrequest.Proxy = GlobalProxySelection.GetEmptyWebProxy(); 
               } 
               //設置其他的herader 
               webrequest =WebRequestSetHeaders(webrequest); 
               if (!String.IsNullOrEmpty(refer)) 
               { 
                   webrequest.Referer = refer; 
               } 
               else 
               { 
                   webrequest.Referer = webUrl; 
               } 
               webrequest.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip,deflate"); 
               webrequest.CookieContainer = cookieContainer; 
               webrequest.Timeout = 5000; 
               webrequest.UserAgent = "User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)"; 
               webrequest.Accept = "*/*"; 
               webrequest.KeepAlive = true; 
               webrequest.Headers.Add("Accept-Language", "zh-cn,en-us;q=0.5"); 
 
               using (HttpWebResponse response = (HttpWebResponse)webrequest.GetResponse()) 
               { 
 
                   if (response.ContentEncoding.ToLower().Contains("gzip")) 
                   { 
                       using (GZipStream stream = new GZipStream(response.GetResponseStream(), CompressionMode.Decompress)) 
                       { 
                           using (StreamReader reader = new StreamReader(stream, Encoding.UTF8)) 
                           { 
 
                               model.html = reader.ReadToEnd(); 
                           } 
                       } 
                   } 
                   else if (response.ContentEncoding.ToLower().Contains("deflate")) 
                   { 
                       using (DeflateStream stream = new DeflateStream(response.GetResponseStream(), CompressionMode.Decompress)) 
                       { 
                           using (StreamReader reader = new StreamReader(stream, Encoding.UTF8)) 
                           { 
 
                               model.html = reader.ReadToEnd(); 
                           } 
 
                       } 
                   } 
                   else 
                   { 
                       using (Stream stream = response.GetResponseStream()) 
                       { 
                           using (StreamReader reader = new StreamReader(stream, Encoding.UTF8)) 
                           { 
 
                               model.html = reader.ReadToEnd(); 
                           } 
                       } 
                   } 
               } 
           } 
           catch (Exception ex) 
           { 
               model.exception = ex; 
               model.html = string.Empty; 
 
           } 
           model.cookieContainer = cookieContainer; 
           return model; 
       }