/// <summary>

        /// 获取本周的周一日期

        /// </summary>

        /// <returns></returns>

        public static string GetThisWeekMonday()

        {

            DateTime date = DateTime.Now;

            DateTime firstDate = System.DateTime.Now;

            switch (date.DayOfWeek)

            {

                case System.DayOfWeek.Monday:

                    firstDate = date;

                    break;

                case System.DayOfWeek.Tuesday:

                    firstDate = date.AddDays(-);

                    break;

                case System.DayOfWeek.Wednesday:

                    firstDate = date.AddDays(-);

                    break;

                case System.DayOfWeek.Thursday:

                    firstDate = date.AddDays(-);

                    break;

                case System.DayOfWeek.Friday:

                    firstDate = date.AddDays(-);

                    break;

                case System.DayOfWeek.Saturday:

                    firstDate = date.AddDays(-);

                    break;

                case System.DayOfWeek.Sunday:

                    firstDate = date.AddDays(-);

                    break;

            }

            return firstDate.ToString("yyyy-MM-dd");

        }