201112180659 ,这样的日期格式如何转换

 
string str = "201112180659";
        if (str.Length >= 12)
        {
            string sNew = str.Substring(0, 4) + "-" + str.Substring(4, 2) + "-" + str.Substring(6, 2) + " " + str.Substring(8, 2) + ":" + str.Substring(10, 2);

            DateTime date = Convert.ToDateTime(sNew);
        }

void Main()
{
    Console.WriteLine(DateTime.ParseExact("201112180659","yyyyMMddHHmm",null).ToString("yyyy-MM-dd HH:mm"));
    //2011-12-18 06:59
}