排名项目与LINQ名单 [英] Ranking items in a list with LINQ

问题描述

我试图找出一种方法来在列表项目排序，并保持结果的对象或其他列表。我知道的排序依据的方法，但我并不确切地知道如何去创造每一个项目对应的排名。

I am trying to figure out a way to rank items in a list, and hold the results in an object or another list. I know about the orderby method, but I don't exactly know how to go about creating a corresponding rank number for each item.

例如：

List<int> numbers = new List<int>();

numbers.Add(650);
numbers.Add(150);
numbers.Add(500);
numbers.Add(200);

，然后存储结果无论从低到高或高到低的位置：

and then store the results from either low to high or high to low here:

public class NumberRank
{
    public int Number {get; set;}
    public int Rank {get; set;}

    public NumberRank(int number)
    {
        Number = number;
        Rank = ????????;
    }
}

通过LINQ任何解决方案？

Any solutions through LINQ?

推荐答案

这应该做到这一点：

public class NumberRank
{
   public int Number {get; set;}
   public int Rank {get; set;}

   public NumberRank(int number, int rank)
   {
      Number = number;
      Rank = rank;
   }
}

class Test
{
   static void Main()
   {
      List<int> numbers = new List<int>();

      numbers.Add(650);
      numbers.Add(150);
      numbers.Add(500);
      numbers.Add(200);

      List<NumberRank> numberRanks = numbers.OrderByDescending(n => n).Select((n, i) => new NumberRank(n, i + 1)).ToList();

      // check it worked
      foreach(NumberRank nr in numberRanks) Console.WriteLine("{0} : {1}", nr.Rank, nr.Number);
      Console.ReadKey();  
   }
}

要排名升序排列（即最低数量的第一），那么只需更换OrderByDescending通过排序依据。

To rank in ascending order (i.e. lowest number first), then just replace OrderByDescending by OrderBy.

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