Lambda表达式中的OrderByDescending？

Question

以下是我想要按日期值获取订单的代码。任何人都可以帮我解决问题吗？

pointsCore.Categories
          .Where(d => d.EventCount != WebUi.NOCOUNT)
          .SelectMany(c => c.Events)
          .Select( x => Convert.ToDateTime(x.EventDate)
                               .ToString("MMM"))
          .Distinct()
          .ToList();

Answer 1

当然 - 只需在之前添加，然后转换为字符串月份名称：

pointsCore.Categories
          .Where(d => d.EventCount != WebUi.NOCOUNT)
          .SelectMany(c => c.Events)
          .OrderByDescending(x => x.EventDate)     // <-----------
          .Select( x => Convert.ToDateTime(x.EventDate)
                               .ToString("MMM"))
          .Distinct()
          .ToList();

Answer 2

您只需在OrderByDescending上添加LINQ EventDate：

pointsCore.Categories.Where(d => d.EventCount != WebUi.NOCOUNT)
          .SelectMany(c => c.Events)
          .OrderByDescending(d => d.EventDate)
          .Select(x => Convert.ToDateTime(x.EventDate).ToString("MMM"))
          .Distinct()
          .ToList();

Answer 3

您希望在转换为字符串格式之前进行排序。我也会在排序和格式化之前做区分：

pointsCore.Categories
        .Where(d => d.EventCount != WebUi.NOCOUNT)
        .SelectMany(c => c.Events)
        .Distinct()
        .OrderByDescending(ev => ev.EventDate)
        .Select( x => Convert.ToDateTime(x.EventDate)
                           .ToString("MMM"))         
        .ToList();