拆分日期/周列表为a和b周LINQ

Question

的datesList查询只是一个日期时间值的列表。

随着LINQ查询/ GROUPBY I组所有那些属于某一周在今年进入分组天。

Func<DateTime, int> weekProjector = d => 
CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(d, CalendarWeekRule.FirstDay, DayOfWeek.Monday); 

var weeks = (from date in datesList group date by weekProjector(date.Date)).ToList(); 

让我们假设星期收集包含8，并可以旋转A和B星期。这意味着，如果该用户与周开始通过值2的转动传递该结果：

AA，BB，AA，BB（8周，每周一次旋转是2）

AAAA，BBBB（8周，每周旋转4）

我怎样才能查询周收集和组/项目或任何日期时间值到一个单独weekListA/weekListB用考虑，其可以是从1的任何数量到8

UPDATE旋转值：

最终状态是2个列表A和B列表，每个列表包含周收集的日期时间值。

更新2：在这个样本每周轮换将有因素4：这意味着我有4周A型，4周B型等

Answer 1

我希望我理解正确你。

给定一串日期，由今年星期分组：

// some testdata 
var datesList = Enumerable.Range(0, 8).Select (e => DateTime.Now.AddDays(7 * e)).ToList(); 

Func<DateTime, int> weekProjector = d => 
    CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(d, CalendarWeekRule.FirstDay, DayOfWeek.Monday); 

var weeks = datesList.GroupBy(weekProjector).ToList(); 

你应该得到你想要通过这个查询结果：

var result = weeks.OrderBy(w => w.Key) 
        .Select((g, i) => new {WeekType = (i/rotation) % 2, Week = g}) 
        .GroupBy(w => w.WeekType) 
        .ToList(); 

其中rotation是你的“旋转” （2或4）和2是要（组A和B => 2基团）基团的数目。

您可能要添加到Select的GroupBy后，只选择你想要的数据，例如：

var weekA = result.Where(r => r.Key==0).Select(g => g).SelectMany(g => g).SelectMany(a => a.Week).ToList(); 
var weekB = result.Where(r => r.Key==1).Select(g => g).SelectMany(g => g).SelectMany(a => a.Week).ToList(); 

---

更可读/通用的解决方案：

void Rotate<TResult, TGroup>(IEnumerable<TResult> datesList, Func<TResult, TGroup> grouper, int rotation, out List<TResult> listA, out List<TResult> listB) 
{ 
    listA = new List<TResult>(); 
    listB = new List<TResult>(); 

    var weeks = datesList.GroupBy(grouper).ToList(); 

    var c_rotation = 0; 
    var c_list = listA; 

    using (var en = weeks.GetEnumerator()) 
     while(en.MoveNext()) 
     { 
      c_list.AddRange((IGrouping<TGroup, TResult>)en.Current); 
      c_rotation++; 
      if (c_rotation == rotation) 
      { 
       c_rotation = 0; 
       c_list = c_list == listA ? listB : listA; 
      } 
     } 
} 

使用它喜欢：

List<DateTime> listA; 
List<DateTime> listB; 

Func<DateTime, int> weekProjector = d => 
    CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(d, CalendarWeekRule.FirstDay, DayOfWeek.Monday); 

Rotate(datesList, weekProjector, 2, out listA, out listB); 

Answer 2

这可能是什么你要找的，GroupBy Index % 2：

var abRotations = datesList 
    .GroupBy(d => CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(d, CalendarWeekRule.FirstDay, DayOfWeek.Monday)) 
    .Select((wg, i) => new { WeekGroup = wg, Index = i }) 
    .GroupBy(x => x.Index % 2); 

List<DateTime> A_Rotation = abRotations.First().SelectMany(x => x.WeekGroup).ToList(); 
List<DateTime> B_Rotation = abRotations.Last().SelectMany(x => x.WeekGroup).ToList(); 

DEMO