C#获取指定网页源码的几种方法

       // WebClient
       private string GetWebClient(string url)
        {
            string strHTML = "";
            WebClient myWebClient = new WebClient();
            Stream myStream = myWebClient.OpenRead(url);
            StreamReader sr = new StreamReader(myStream, System.Text.Encoding.GetEncoding("utf-8"));
            strHTML = sr.ReadToEnd();
            myStream.Close();
            return strHTML;
        }

        // WebRequest
        private string GetWebRequest(string url)
        {
            Uri uri = new Uri(url);
            WebRequest myReq = WebRequest.Create(uri);
            WebResponse result = myReq.GetResponse();
            Stream receviceStream = result.GetResponseStream();
            StreamReader readerOfStream = new StreamReader(receviceStream,System.Text.Encoding.GetEncoding("gb2312"));
            string strHTML = readerOfStream.ReadToEnd();
            readerOfStream.Close();
            receviceStream.Close();
            result.Close();
            return strHTML;
        }

        // HttpWebRequest
        private string GetHttpWebRequest(string url)
        {
            try
            {
                Uri uri = new Uri(url);
                HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(uri);
                myReq.UserAgent = "User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705";
                myReq.Accept = "*/*";
                myReq.KeepAlive = true;
                myReq.Headers.Add("Accept-Language", "zh-cn,en-us;q=0.5");
                HttpWebResponse result = (HttpWebResponse)myReq.GetResponse();
                Stream receviceStream = result.GetResponseStream();
                StreamReader readerOfStream = new StreamReader(receviceStream, System.Text.Encoding.GetEncoding("gb2312"));
                string strHTML = readerOfStream.ReadToEnd();
                readerOfStream.Close();
                receviceStream.Close();
                result.Close();
                
                return strHTML;
            }
            catch (Exception ex)
            {
                throw new Exception("采集指定网址异常，" + ex.Message);
            }
        }

// 获取网页源码，如果启用了gzip压缩后页面获取会产生乱码，采用此方法可解决gzip压缩而产生的乱码情况
       private string GetHtmlCode(string url)
       {
           string htmlCode;
           HttpWebRequest webRequest = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(url);
            webRequest.Timeout = 30000;
            webRequest.Method = "GET";
            webRequest.UserAgent = "Mozilla/4.0";
            webRequest.Headers.Add("Accept-Encoding", "gzip, deflate");
            HttpWebResponse webResponse = (System.Net.HttpWebResponse)webRequest.GetResponse();
            if (webResponse.ContentEncoding.ToLower() == "gzip")//如果使用了GZip则先解压            {
                using (System.IO.Stream streamReceive = webResponse.GetResponseStream())
                {
                    using (var zipStream =
                        new System.IO.Compression.GZipStream(streamReceive, System.IO.Compression.CompressionMode.Decompress))
                    {
                        using (StreamReader sr = new System.IO.StreamReader(zipStream, Encoding.Default))
                        {
                            htmlCode = sr.ReadToEnd();
                        }
                    }
                }
            }
            else
            {
                using (System.IO.Stream streamReceive = webResponse.GetResponseStream())
                {
                    using (System.IO.StreamReader sr = new System.IO.StreamReader(streamReceive, Encoding.Default))
                    {
                        htmlCode = sr.ReadToEnd();
                    }
                }
            }

            return htmlCode;
        }