【轉載】HttpWebRequest開啟gz2.對接收到的流進行解碼：

PRivate string GetResponseBody(HttpWebResponse response){    string responseBody = string.Empty;    if (response.ContentEncoding.ToLower().Contains("gzip"))            　　{        using (GZipStream stream = new GZipStream(response.GetResponseStream(), CompressionMode.Decompress))        {            using (StreamReaderreader = new StreamReader(stream))            {                responseBody = 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))            {                responseBody = reader.ReadToEnd();            }        }    }    else    {        using (Stream stream = response.GetResponseStream())        {            using (StreamReader reader =  new StreamReader(stream, Encoding.UTF8))            {                responseBody = reader.ReadToEnd();            }        }    }    return responseBody;}

轉自：http://www.csharpwin.com/csharpspace/13345r5893.shtml