Http请求类

public class HttpHelper
    {
        /// <summary>
        /// 证书校验
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="certificate"></param>
        /// <param name="chain"></param>
        /// <param name="errors"></param>
        /// <returns></returns>
        //public static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        //{   
        //    // 总是接受  
        //    return true;
        //}
        /// <summary>
        /// HttpGet
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="url"></param>
        /// <returns></returns>
        public static T HttpGet<T>(string url)
        {
            Stream stream = null;
            StreamReader sr = null;
            try
            {
                WebRequest ret = WebRequest.Create(url);
                ret.Method = "Get";
                ret.ContentType = "application/json;charset=UTF-8";
                HttpWebResponse response = (HttpWebResponse)ret.GetResponse();
                stream = ret.GetResponse().GetResponseStream();
                sr = new StreamReader(stream, Encoding.UTF8);
                string ApiResult = sr.ReadToEnd();
                var t = (T)JsonConvert.DeserializeObject<T>(ApiResult);
                return t;
            }
            catch
            {
                throw;
            }
            finally
            {
                stream.Close();
                sr.Close();
            }
        }
        /// <summary>