C# 非空字段按照ASCII码从小到大排序（字典序）

 public static void requestPay()
        {


            Dictionary<string, string> dics = new Dictionary<string, string>();
            dics.Add("amount", amount);
            dics.Add("callback_url", callback_url);
            dics.Add("goodsname", goodsname);
            dics.Add("merchno", merchno);
            dics.Add("notify_url", notify_url);
            dics.Add("ordno", ordno);
            dics.Add("organno", organno);
            dics.Add("version", version);
            dics.Add("paytype", paytype);

            getParamSrc(dics);

        }

        public static String getParamSrc(Dictionary<string, string> paramsMap)
        {

            var vDic = (from objDic in paramsMap orderby objDic.Key ascending select objDic);
            StringBuilder str = new StringBuilder();
            foreach (KeyValuePair<string, string> kv in vDic)
            {
                string pkey = kv.Key;
                string pvalue = kv.Value;
                str.Append(pkey + "=" + pvalue + "&");
            }

            String result = str.ToString().Substring(0, str.ToString().Length - 1);
            return result;

        }