在列表中排序月份和年份

Question

I have a list of strings where each string is a month + year. I found similar question here but It was list with months only. So my list looks like that

List<string> monthsList = new List<string>();
       monthsList.Add("August 2015");
       monthsList.Add("June 2014");
       monthsList.Add("February 2014");
       monthsList.Add("June 2015");

Is there a way to order it like that?

February 2014
June 2014
June 2015
August 2015

Answer 1

Make sure that you change the DateTime.Parse format to so that it accounts for the year in addition to the month:

DateTime.ParseExact(x, "MMMM yyyy", CultureInfo.InvariantCulture)

And then make sure that you change the OrderBy key selector so that it considers the entire date and not only the month when performing the sort:

.OrderBy(x => x.Sort)

The complete code will look like this:

var sortedMonths = monthsList
    .Select(x => new { Name = x, Sort = DateTime.ParseExact(x, "MMMM yyyy", CultureInfo.InvariantCulture) })
    .OrderBy(x => x.Sort)
    .Select(x => x.Name)
    .ToArray();

Answer 2

This is something I built. It works like a charm. See image for example of output.

 public class MonthAndYear 
    {        
        private string _monthAndYear;

        public string Month { get; set; }
        public IDictionary<string, int> Months { get; set; }
        public int Year { get; set; }
        public string MonthYear
        {
            get
            {
                return string.Concat(Month," ", Year);
            }
            set
            {
                _monthAndYear = value;
            }
        }

        public MonthAndYear()
        {
            Months = new Dictionary<string, int>();
            Months.Add("January", 1);
            Months.Add("February", 2);
            Months.Add("March", 3);
            Months.Add("April", 4);
            Months.Add("May", 5);
            Months.Add("June", 6);
            Months.Add("July", 7);
            Months.Add("August", 8);
            Months.Add("September", 9);
            Months.Add("October", 10);
            Months.Add("November", 11);
            Months.Add("December", 12);
        }        

        public int MonthInteger(string month)
        {
            if (Months.ContainsKey(month))
            {
                return Months[month];
            }
            else
                return 1;
        }

        public List<MonthAndYear> SortMonthAndYear(List<string> _monthYearList)
        {           
            List<MonthAndYear> _sortedMonthAndYear = new List<MonthAndYear>();

            foreach (var _monthYear in _monthYearList)
            {
                _sortedMonthAndYear.Add
                (
                    new MonthAndYear
                    {
                        Month = _monthYear.Substring(0, _monthYear.IndexOf(' ')),
                        Year = Convert.ToInt32(_monthYear.Substring(Math.Max(0, _monthYear.Length - 4)))
                    }
                );
            }            
            return _sortedMonthAndYear.OrderBy(y => y.Year).ThenBy(m => m.MonthInteger(m.Month)).ToList(); 
        }

    }