C# JSON 日期转换

public string ToJson<T>(T t)
{
JavaScriptSerializer jss = new JavaScriptSerializer();
var json = jss.Serialize(t);
MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString);
Regex reg = new Regex(@"\\/Date\((\d+)\)\\/");
var newjson = reg.Replace(json,matchEvaluator);
return newjson;
}

public string ConvertJsonDateToDateString(Match m)
{
string result = string.Empty();
DateTime dt = new DateTime();
var timevalue = m.Groups[0].Value.Replace("\\/Date(“,"").Replace(")\\/","");
long newtime = long.Parse(timevalue);
dt =  dt.AddMilliseconds(newtime);
result = dt.ToString("yyyy-MM-dd HH:mm:ss");
return result;
}