将 List<T> 的部分拆分为 2 个 List<T> 并加入这 2 个

Question

过去几个小时我一直被这个问题困扰，希望您能帮助我。

我有一个包含数据的列表（请参阅类：allItems），但我想拆分数据，因此类项包含所有数据，而公共列表包含子项。

在这个 sn-p 中发生的情况是，在 for 循环期间，项目会以相同的值添加到天数列表中，这就是我很难尝试将正确数量的条目添加到天数列表中的地方同一周数多次出现在 allStats 列表中。

任何帮助将不胜感激，谢谢。

public class allItems
{
    public DateTime PunchInDate { get; set; }
    public DateTime PunchOutDate { get; set; }
    public DayOfWeek DayOfWeek { get; set; }
    public int WeekNumber { get; set; }
    public int MonthNumber { get; set; }
    public bool PunchedInLate { get; set; }
    public bool PunchedOutLate { get; set; }
}
public class items
{
    public int WeekNumber { get; set; }
    public int MonthNumber { get; set; }
    public List<subItems> Days { get; set; }
}
public class subItems
{
    public bool PunchedInLate { get; set; }
    public bool PunchedOutLate { get; set; }
    public DateTime PunchInDate { get; set; }
    public DateTime PunchOutDate { get; set; }
    public DayOfWeek DayOfWeek { get; set; } 
}
protected int getNumberOfWeeks(List<allItems> list, int numberToFind)
{
    List<allItems> results = list.FindAll(
        delegate(allItems ai)
        {
            return ai.WeekNumber == numberToFind;
        }
        );
    return results.Count;
}
public List<items> getStats(string userId, string type)
{
    List<allItems> allStats = getAllStats(userId, "week");
    List<items> stats = new List<items>();

    foreach (allItems allItem in allStats)
    {
        items item = new items();
        subItems subItem = new subItems();
        List<subItems> Days = new List<subItems>();

        item.MonthNumber = allItem.MonthNumber;
        item.WeekNumber = allItem.WeekNumber;
        item.Days = Days;

        int numberOfWeeks = getNumberOfWeeks(allStats, allItem.WeekNumber);
        for (int i = 0; i < numberOfWeeks; i++)
        {
            subItem.DayOfWeek = allItem.DayOfWeek;
            subItem.PunchedInLate = allItem.PunchedInLate;
            subItem.PunchedOutLate = allItem.PunchedOutLate;
            subItem.punchInDate = allItem.PunchInDate;
            subItem.PunchOutDate = allItem.PunchOutDate;

            Days.Add(subItem);
        }

        items result = stats.Find(week => week.WeekNumber == allItem.WeekNumber);

        if (result == null)
        {
            stats.Add(item);
        }
    }

    return stats;
}

Answer 1

听起来你可以用 linq 做到这一点：

var allItemsList = new List<allItems>() { ... fill in items ... };
var asItems = 
    from item in allItemsList
    group item by new { week = item.weekNumber, month = item.monthNumber } into byWeekMonth
    select new items()
    {
        weekNumber = byWeekMonth.Key.week,
        monthNumber = byWeekMonth.Key.month,
        days = byWeekMonth.Select(si => 
            new subItems()
            {
                punchedInLate = si.punchedInLate,
                punchedOutLate = si.punchedOutLate,
                // etc, other fields
            }).ToList()
    };