日期和值的字典,在LINQ中查找每年的最大日期值

var dates = new[] { new DateTime(2021, 1, 1), new DateTime(2021, 2, 1), new DateTime(2021, 3, 1), new DateTime(2022, 1, 1), new DateTime(2022, 2, 1), new DateTime(2022, 3, 1) };

var maxDatesByYear = from date in dates
                     group date by date.Year into yearGroup
                     select new { Year = yearGroup.Key, MaxDate = yearGroup.Max() };

foreach (var item in maxDatesByYear)
{
    Console.WriteLine($"Year: {item.Year}, Max Date: {item.MaxDate}");
}