使用Linq在List中获取月份和年份

Question

我有一个这样的列表

 public class Result
{
    public string id { get; set; }
    public string name { get; set; }
    public string startDate { get; set; } //smaple date 2014-03-31T12:30:03
}
List<Result>

我想获取列表中所有不同的月份。我试过这样做

  List<string> monthNamesList = eventListResponse.result.Select(s => Convert.ToDateTime(s.startDate).ToString("MMMM")).Distinct().ToList();

它完成了任务，唯一的问题是如果列表包含两个元素

2014-03-31T12:30:03
2013-03-31T12:30:03

我的代码将只返回一个月，在那里我想得到它像2014 March和2013 March。所以我创建了一个新的模型类，带有年和月

 public class MonthYearMOdel
{
    public string month;
    public string year;
}

有谁能指出我如何从我的第一个列表中获取不同的月份并存储在List<MonthYearMOdel>中。其中2014 March和2013 March均存储

Answer 1

try this:

List<MonthYearMOdel> monthNamesList = eventListResponse.result.Select(s => new
    {
        M = Convert.ToDateTime(s.startDate).ToString("MMMM"),
        Y = Convert.ToDateTime(s.startDate).ToString("yyyy")
    })
    .Distinct()
    .Select(u => new MonthYearMOdel()
        {
            month = u.M,
            year = u.Y,
        })
    .ToList();

Answer 2

简单的方法(每个字符串包含月份和年份):

List<string> monthNamesList = eventListResponse.result.Select(s => Convert.ToDateTime(s.startDate).ToString("yyyy MMMM")).Distinct().ToList();

With MonthYearModel:

public class MonthYearModel
{
    public string month;
    public string year;
    public MonthYearModel(string dateTime)
    {
        var date = Convert.ToDateTime(dateTime);
        this.month = date.ToString("MMMM");
        this.year = date.ToString("yyyy");
    }
    public bool Equals(object arg)
    {
        var model = arg as MonthYearModel;
        return (model != null) && model.month == this.month && model.year == this.year;
    }
    public int GetHashCode()
    {
        return (month.GetHashCode() * 397) ^ year.GetHashCode();
    }
}
List<MonthYearModel> = eventListResponse.result.Select(s => new MonthYearModel(s.startDate)).Distinct().ToList();