HttpWebRequest对像中的头加入("Accept-Encoding", "gzip"); 返回的数据进行解密。

//下载网页
  private string GetData (string 要下载的网址, string 当前网址)
  {
   string text1 = "";
   string name = "gb2312";
   name = "Big5";
   try
   {
    HttpWebRequest HWR = (HttpWebRequest) WebRequest.Create(要下载的网址);
    HWR.Timeout = 20;
    HWR.ReadWriteTimeout = 30;
    HWR.UserAgent = "User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Maxthon; .NET CLR 1.1.4322)";
    HWR.Accept = "*/*";
    HWR.KeepAlive = true;
    HWR.Headers.Add("Accept-Language", "zh-cn,en-us;q=0.5");
    HWR.Headers.Add("Accept-Encoding", "gzip, deflate");
    HWR.Referer = 当前网址;
    HWR.CookieContainer = New CookieContainer();
    HttpWebResponse HWResp = (HttpWebResponse) HWR.GetResponse();
    Stream stream1 = Gzip(HWResp);
    StreamReader reader1 = new StreamReader(stream1, Encoding.GetEncoding(name));
    text1 = reader1.ReadToEnd();
    reader1.Close();
    stream1.Close();
   }
   catch
   {
    text1="";
   }
   return text1;
  }

//解密
private Stream Gzip (HttpWebResponse HWResp)
  {
   Stream stream1 = null;
   if (HWResp.ContentEncoding == "gzip")
   {
    stream1 = new GZipInputStream(HWResp.GetResponseStream());
   }
   else
   {
    if (HWResp.ContentEncoding == "deflate")
    {
     stream1 = new InflaterInputStream(HWResp.GetResponseStream());
    }
   }
   if (stream1 == null)
   {
    return HWResp.GetResponseStream();
   }
   MemoryStream stream2 = new MemoryStream();
   int count = 0x800;
   byte[] buffer = new byte[0x800];
   goto A;
   A:
    count = stream1.Read(buffer, 0, count);
   if (count > 0)
   {
    stream2.Write(buffer, 0, count);
    goto A;
   }
   stream2.Seek((long) 0, SeekOrigin.Begin);
   return stream2;
  }