C#秒转时间timeStampToString

public static string timeStampToString(int time)
{
    long ltime = (long )time;
    DateTime t = new DateTime(time * TimeSpan.TicksPerSecond);
    t = t. ToLocalTime();
    int year = t.Year + 1969 ;
    string syear = "" + year;
    int month = t.Month ;
    string smonth = month < 10 ? "0" + month : "" + month;
    int day = t.Day;
    string sday = day < 10 ? "0" + day : "" + day;
    int hour = t.Hour;
    string shour = hour < 10 ? "0" + hour : "" + hour;
    int minute = t.Minute ;
    string sminute = minute < 10 ? "0" + minute : "" + minute;
    int second = t.Second ;
    string ssecond = second < 10 ? "0" + second : "" + second;

    return syear + "/" + smonth + "/" + sday + " " + shour + ":" + sminute + ":" + ssecond;
}