C#正则表达式 将非标准日期转换成标准日期

        /// <summary>
        /// 将非标准日期修改成标准日期 标准日期 2021-09-01共10位，非标准日期 2021-9-1、2021-09-1、2021-9-01、2021年9月1日、2021年11月1日、2021年9月21日
        /// </summary>
        /// <param name="datetime"></param>
        /// <returns></returns>
        public string GetDate(string datetime)
        {
            //将年月转换成-
            if (Regex.IsMatch(datetime, "日"))
            {
                datetime = Regex.Replace(datetime, @"\D", "-").ToString().Substring(0, Regex.Replace(datetime, @"\D", "-").ToString().Length - 1);
            }
            else
            {
                datetime = Regex.Replace(datetime, @"\D", "-").ToString();
            }
            if (datetime.Length == 10)
            {
                return datetime;
            }
            else
            {
                string year = datetime.Substring(0, 4);
                int index1 = datetime.IndexOf('-', 1);
                int index2 = datetime.LastIndexOf('-');
                string mouth = Regex.Match(datetime, @"-\d{1,2}-").ToString();
                //如果月份是3位则中间补0
                if (mouth.Length == 3)
                {
                    mouth = mouth.Substring(1, 1);
                    mouth = "-" + "0" + mouth + "-";
                }
                //获取第二个-后所有的数字
                var dayex = Regex.Matches(datetime, @"-\d{1,2}");

                //取第二个-后的数字
                string day = dayex[1].ToString();
                day = day.Substring(1, day.Length - 1);
                if (day.Length == 1)
                {
                    day = "0" + day;
                }
                datetime = year + mouth + day;
                return datetime;
            }
        }

 

 

         /// <summary>
        /// 将非标准时间修改成标准时间06:55    非标准时间 6点3分、6点30分、06点3分、06点13分
        /// </summary>
        /// <param name="time"></param>
        /// <returns></returns>
        public string GetTime(string time)
        {
            time = Regex.Replace(time, @"\D", ":").ToString().Substring(0, Regex.Replace(time, @"\D", "-").ToString().Length - 1);
            string hour = Regex.Match(time, @"\d{1,2}:").ToString();
            //截取冒号前面的数字
            hour = hour.Substring(0, hour.Length - 1);
            string minute = Regex.Match(time, @":\d{1,2}").ToString();
            //截取冒号后面的数字
            minute = minute.Substring(1, minute.Length - 1);
            if (hour.Length == 1)
            {
                hour = "0" + hour;
            }
            if (minute.Length == 1)
            {
                minute = "0" + minute;
            }
            time = hour + ":" + minute;
            return time;
        }

 

        /// <summary>
        /// 将非标准时间修改成标准时间06:55  非标准时间 6:5 06:5 6:05 
        /// </summary>
        /// <param name="time"></param>
        /// <returns></returns>
        public string GetTimer(string hour, string minute)
        {
            //截取冒号前面的数字
            hour = hour.Substring(0, hour.Length - 1);
            //截取冒号后面的数字
            minute = minute.Substring(1, minute.Length - 1);
            if (hour.Length == 1)
            {
                hour = "0" + hour;
            }
            if (minute.Length == 1)
            {
                minute = "0" + minute;
            }
            string time = hour + ":" + minute;
            return time;
        }