Question

我有一个日期列表（目前在所选结果中有4000个）我试图将结果放在图表中，

班级看起来像这样

public class DisplayObjectDates
{
    public int Month { get; set; }
    public int Year { get; set; }
    public int day { get; set; }
    public DateTime fulldatetime { get; set; }
    public int CountedDate { get; set; }
}

我有一个班级列表

private static List<DisplayObjectDates> SortedDatesDays = new List<DisplayObjectDates>();

我在从EF调用并获得返回列表

后添加到列表中

if (SortedDatesDays.Count() == 0)
                {
                    var addDisplayObjectDatesYear = new DisplayObjectDates();
                    addDisplayObjectDatesYear.Year = contextreturned.change_time.Year;
                    addDisplayObjectDatesYear.Month = contextreturned.change_time.Month;
                    addDisplayObjectDatesYear.day = contextreturned.change_time.Day;
                    addDisplayObjectDatesYear.fulldatetime = contextreturned.change_time;
                    addDisplayObjectDatesYear.CountedDate = 1;
                    SortedDatesDays.Add(addDisplayObjectDatesYear);
                }
                else
                {
                    foreach (var VARIABLE in SortedDatesDays)
                    {
                        if (VARIABLE.day == contextreturned.change_time.Day && VARIABLE.Month == contextreturned.change_time.Month && VARIABLE.Year == contextreturned.change_time.Year)
                        {
                            VARIABLE.CountedDate = VARIABLE.CountedDate++;
                        }
                        else
                        {
                            var addDisplayObjectDatesYear = new DisplayObjectDates();
                            addDisplayObjectDatesYear.Year = contextreturned.change_time.Year;
                            addDisplayObjectDatesYear.Month = contextreturned.change_time.Month;
                            addDisplayObjectDatesYear.day = contextreturned.change_time.Day;
                            addDisplayObjectDatesYear.fulldatetime = contextreturned.change_time;
                            addDisplayObjectDatesYear.CountedDate = 1;
                            SortedDatesDays.Add(addDisplayObjectDatesYear);
                        }
                    }
                }

这给了我一个错误收集被修改;枚举操作可能无法执行。

所以我改变了

 foreach (var VARIABLE in SortedDatesDays)

到

foreach (var VARIABLE in SortedDatesDays.ToList())

现在我内存不足

在一天结束时，我需要计算在某个特定日期发生的事件的次数我需要把它放到一个我可以在图表中使用的表格中（DEVEXPRESS）我不确定我是否应该使用linq或当前系统。所有想法的任何帮助与这样做的正确方式将不胜感激谢谢 a0011010011

Answer 1

我实际上认为foreach (var VARIABLE in SortedDatesDays.ToArray())会解决问题，因为我经常使用它。

在这种情况下，请尝试以下操作。

...
else
{
    // create a temporary collection for storing new items
    var list = new List<DisplayObjectDates>();

    foreach (var VARIABLE in SortedDatesDays)
    {
         if (...) { ... }
         else
         {
              var addDisplayObjectDatesYear = new DisplayObjectDates();
              ...
              // place it to the new list instead
              list.Add(addDisplayObjectDatesYear);
         }
     }

     // merge lists
     SortedDatesDays.AddRange(list);
}

Answer 2

虽然你正在分配 FullDateTime DisplayObjectDates对象...我更喜欢说你重建你的课程可能是这样的...它也有助于你的程序使用较少的memery ..

public class DisplayObjectDates
    {
        public int Month { get { return fulldatetime.Month; } }
        public int Year { get { return fulldatetime.Year; } }
        public int day { get { return fulldatetime.Day; } }
        public DateTime fulldatetime { get; set; }
        public int CountedDate { get; set; }
    }

然后对初始化函数进行排序

if (SortedDatesDays.Count() == 0)
        {
            var addDisplayObjectDatesYear = new DisplayObjectDates();                 
            addDisplayObjectDatesYear.fulldatetime = contextreturned.change_time;
            addDisplayObjectDatesYear.CountedDate = 1;
            SortedDatesDays.Add(addDisplayObjectDatesYear);
        }
        else
        {
            foreach (var VARIABLE in SortedDatesDays)
            {
                if (VARIABLE.fulldatetime.Date == contextreturned.change_time.fulldatetime.Date)
                {
                    VARIABLE.CountedDate = VARIABLE.CountedDate++;
                }
                else
                {
                    var addDisplayObjectDatesYear = new DisplayObjectDates();
                    addDisplayObjectDatesYear.fulldatetime = contextreturned.change_time;
                    addDisplayObjectDatesYear.CountedDate = 1;
                    SortedDatesDays.Add(addDisplayObjectDatesYear);
                }
            }
        }

c＃add to list <datecount> - DateTime Best way </datecount>

2 个答案: