c#获取html

[墨香年少 32]

private string getHTML(string url)
        {
            if (url.Substring(0, 4) != "http")
            {
                return "error";
            }
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "GET";
            try
            {
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                if (response.StatusCode.ToString() != "OK")
                {
                    return "error";
                }

                if (response.StatusCode == HttpStatusCode.NotFound)
                    return "error";
                if (response.StatusCode == HttpStatusCode.InternalServerError)
                    return "error";
                if (response.StatusCode == HttpStatusCode.BadGateway)
                    return "error";
                Stream ResponseStream = response.GetResponseStream();
                StreamReader sr = new StreamReader(ResponseStream, Encoding.UTF8);
                string html = sr.ReadToEnd();
                sr.Close();
                ResponseStream.Close();
                return html;
            }
            catch (Exception e)
            {
                return "error";
            }
            return "error";
        }