按OrderBy，ThenBy排序 [英] Sorting with OrderBy, ThenBy

问题描述

我试图根据上一个已排序的列对一个表的几个列进行排序. 对于前两列，它工作正常.但是，当我对第三列进行排序时，第二列就失去了排序.据我所知，我的foreach循环肯定有问题.这是我的排序代码:

I'm trying to sort several columns of a table depending of the previous sorted column. It works fine for the first two columns. But as soon as I sort the third column the second one loses its sort. As far as I know for now there must be a problem with my foreach loop. Here is my code for sorting:

public List<object> inhaltSortieren(List<object> zuSortierendeListe, Dictionary<string, SortierRichtung> sortierung)
{
    IOrderedEnumerable<object> sortierteListe = null;
    if (sortierung.First().Value == SortierRichtung.asc)
        sortierteListe = zuSortierendeListe.OrderBy(x => x.GetType().GetProperty(sortierung.First().Key).GetValue(x, null));
    else if (sortierung.First().Value == SortierRichtung.desc)
        sortierteListe = zuSortierendeListe.OrderByDescending(x => x.GetType().GetProperty(sortierung.First().Key).GetValue(x, null));
    bool first = true;
    foreach (KeyValuePair<string, SortierRichtung> spalte in sortierung)
    {
        if (first)
        {
            first = false;
            continue;
        }
        if (spalte.Value == SortierRichtung.asc)
            sortierteListe = sortierteListe.ThenBy(x => x.GetType().GetProperty(spalte.Key).GetValue(x, null));
        else if (spalte.Value == SortierRichtung.desc)
            sortierteListe = sortierteListe.ThenByDescending(x => x.GetType().GetProperty(spalte.Key).GetValue(x, null));
    }

    return sortierteListe.ToList();
 }

有什么想法吗?

更新:也许我要添加一些其他信息:

Update: Maybe I add some further information:

• @param zusortierendeListe:这是我要排序的列表，它是对象列表
• @param sortierung:这是我要排序，升序或降序的方向

对象本身就是表数据列表

The objects themselves are Lists of Tabledata

推荐答案

您正在传递Dictionary;将Dictionary用作IEnumerable<KeyValuePair>时，从Dictionary中获取值的顺序(就像您的foreach循环一样)(可能)不是添加它们的顺序！

You're passing in a Dictionary; the order in which you get values out of a Dictionary when you use it as an IEnumerable<KeyValuePair> (as your foreach loop does) is (probably) not the order in which you added them!

您将需要使用List<KeyValuePair>(或其他一些有序 IEnumerable<KeyValuePair>)代替Dictionary，甚至需要创建一个自定义类来保存字段和方向并传递的List.

You'll need to use a List<KeyValuePair> (or some other ordered IEnumerable<KeyValuePair>) instead of the Dictionary, or even create a custom class to hold the field and direction and pass a List of that.

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