HTTP协议获取网页内容

HTTP协议获取网页内容：

  protected string GetPageInfo(string url, bool needHeard, string referer)
        {
            StringBuilder sb = new StringBuilder();
            HttpWebRequest request;
            try
            {
                request = (HttpWebRequest)(WebRequest.Create(url));
                if (needHeard)
                {
                    request.Method = "GET";
                    request.Headers.Add(HttpRequestHeader.AcceptLanguage, "en-US");
                    request.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip, deflate");
                    request.Referer = referer;
                    request.Accept = "application/javascript, */*;q=0.8";
                    request.UserAgent = "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)";
                }
            }
            catch (Exception e)
            {
                return e.Message;
            }
            request.KeepAlive = false;
            HttpWebResponse response;
            try
            {
                response = (HttpWebResponse)request.GetResponse();
                System.Text.Encoding encoding = System.Text.Encoding.Default;
                Stream streamResponse = response.GetResponseStream();
                StreamReader streamReader = new StreamReader(streamResponse, encoding);
                Char[] readBuff = new Char[256];
                int count = streamReader.Read(readBuff, 0, 256);
                while (count > 0)
                {
                    String outputData = new String(readBuff, 0, count);
                    sb.Append(outputData);
                    count = streamReader.Read(readBuff, 0, 256);
                }
                response.Close();
                return sb.ToString();
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
        }