C# json日期轉換

                #region 日期轉換
                reJson = Regex.Replace(reJson, @"\\/Date\((\d+)\)\\/", match =>
                {
                    DateTime datetime = new DateTime(1970, 1, 1);
                    datetime = datetime.AddMilliseconds(long.Parse(match.Groups[1].Value));
                    datetime = datetime.ToLocalTime();
                    return datetime.ToString("yyyy-MM-dd");
                });
                #endregion

轉換前：

{"iserror":"0","errmsg":"查詢成功","data":[{"cardCTCC":"8924","cardBegin":"\/Date(1491926400000)\/","cardEnd":"\/Date(1523462400000)\/","isBegin":"已激活"}]}

轉換后：

{"iserror":"0","errmsg":"查詢成功","data":[{"cardCTCC":"8924","cardBegin":"2017-04-12","cardEnd":"2018-04-12","isBegin":"已激活"}]}