HttpWebRequest使用問題

最近做一個項目，發現一個非常致命的東西，在用HttpWebRequest的時候 並且銷燬或關閉時一定要注意

HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(strip);
myReq.Method = "GET";

HttpWebResponse myRes = (HttpWebResponse)myReq.GetResponse())

            try
            {         
                    using (StreamReader sr = new StreamReader(myRes.GetResponseStream(), Encoding.GetEncoding("gb2312")))
                    {
                        string XMLstr = sr.ReadToEnd();
                        ds = XMLToDataSet(XMLstr);
                    }
                
            }
            catch (Exception ex)
            {
                OptRong("獲取數據異常，請確認網絡連接良好", ex.ToString());
            }
            finally
            {
                if (myReq != null) { myReq.Abort(); }

                if (myRes != null) { myRes.close(); }
            }

一定要記得判斷一下 他是否爲空 否則會有一定的機率出錯 而且是非常恐怖的錯誤