LINQ сортировка по динамическим параметрам

#c_sharp #net #linq

Прошу помощи в оптимизации LINQ сортировки. Код написанный ниже, был написан по принципу
"ну ведь так же работает?". Но он не красив, не гибок, и хотелось бы понять, как можно
и можно ли через линкью, в качестве параметра для сортировки, указывать List. 

var newItemsReportInfo = new List();
switch (itemsReportInfo[0].SortingTH.Count)
{
    case 0:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
    case 1:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.SortingTH[0], new TechDataComparer())
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
    case 2:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.SortingTH[0], new TechDataComparer())
            .ThenBy(c => c.SortingTH[1], new TechDataComparer())
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
    case 3:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.SortingTH[0], new TechDataComparer())
            .ThenBy(c => c.SortingTH[1], new TechDataComparer())
            .ThenBy(c => c.SortingTH[2], new TechDataComparer())
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
    case 4:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.SortingTH[0], new TechDataComparer())
            .ThenBy(c => c.SortingTH[1], new TechDataComparer())
            .ThenBy(c => c.SortingTH[2], new TechDataComparer())
            .ThenBy(c => c.SortingTH[3], new TechDataComparer())
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
    case 5:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.SortingTH[0], new TechDataComparer())
            .ThenBy(c => c.SortingTH[1], new TechDataComparer())
            .ThenBy(c => c.SortingTH[2], new TechDataComparer())
            .ThenBy(c => c.SortingTH[3], new TechDataComparer())
            .ThenBy(c => c.SortingTH[4], new TechDataComparer())
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
    case 6:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.SortingTH[0], new TechDataComparer())
            .ThenBy(c => c.SortingTH[1], new TechDataComparer())
            .ThenBy(c => c.SortingTH[2], new TechDataComparer())
            .ThenBy(c => c.SortingTH[3], new TechDataComparer())
            .ThenBy(c => c.SortingTH[4], new TechDataComparer())
            .ThenBy(c => c.SortingTH[5], new TechDataComparer())
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
    default:
        newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
            .ThenBy(x => x.SortingTH[0], new TechDataComparer())
            .ThenBy(c => c.SortingTH[1], new TechDataComparer())
            .ThenBy(c => c.SortingTH[2], new TechDataComparer())
            .ThenBy(c => c.SortingTH[3], new TechDataComparer())
            .ThenBy(c => c.SortingTH[4], new TechDataComparer())
            .ThenBy(c => c.SortingTH[5], new TechDataComparer())
            .ThenBy(c => c.SortingTH[6], new TechDataComparer())
            .ThenBy(x => x.Description)
            .ThenBy(x => x.Flieztext)
            .ToList();
        break;
}


Как видно из кода, мы всегда смотрим на размер itemsReportInfo[0].SortingTH и далее
уже применяем один из методов сортировки. Хотелось бы заменить этот код, на код вида.

 newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
     .ThenBy(x => x.SortingTH, new TechDataComparer())
     .ThenBy(x => x.Description)
     .ThenBy(x => x.Flieztext)
     .ToList();

    

Ответы

Ответ 1

Попробуйте что-то в таком стиле: 

var newItemsReportInfo = new List();

var query = itemsReportInfo.OrderBy(x => x.FlyerPos);

for (int i = 0; i < itemsReportInfo[0].SortingTH.Count; i++)
{
    query = query.ThenBy(x => x.SortingTH[i], new TechDataComparer());
}

query = query.ThenBy(x => x.Description);
query = query.ThenBy(x => x.Flieztext);
newItemsReportInfo = query.ToList();


Ответ 2

Вариант с TechDataComparer для List

public class ListTechDataComparer : IComparer>
{
    private IComparer comparer = new TechDataComparer();
    public int Compare(List x, List y)
    {
        for (int i = 0; i < x.Count; i++)
        {
            var compareResult = comparer.Compare(x[i],y[i]);
            if (compareResult != 0) return compareResult;
        }
        return 0;
    }
}


и использовать

newItemsReportInfo = itemsReportInfo.OrderBy(x => x.FlyerPos)
     .ThenBy(x => x.SortingTH, new ListTechDataComparer())
     .ThenBy(x => x.Description)
     .ThenBy(x => x.Flieztext)
     .ToList();