c# - 在列表排序中更改什么以正确排序

Question

我无法完全排序我的列表。它是基于 int 的排序，我使用了 CompareTo() 形式的 IComparable、自定义比较器委托(delegate)和匿名委托(delegate)。这些都不适合我。

代码如下:

[TestMethod]
    public void SortingPlayersFirst()
    {
      //arrange
      Player player = new Player("neosb");
      Player player2 = new Player("simone");
      Player player3 = new Player("Alice");
      player.Score = 5;
      player2.Score = 2;
      player3.Score = 10;
      Players players = new Players();
      players.Add(player);
      players.Add(player2);
      players.Add(player3);

      //I have tried this one
      players.Sort(Player.ComparePlayersByScore);
      //and this one
      players.Sort()
      // and this one
      IComparer<Player> comp = Comparer<Player>.Create(
        (p1, p2) => p1.Score.CompareTo(p2.Score));
      players.Sort(comp);

      //this one fails the test
      Assert.AreEqual(player3, players[0], "Highest score is not first");
      //however this one passes the test
      Assert.AreNotEqual(player2, players[2], "Lowest score is not last");
    }

public class Players : List<Player>
  {

  }

public class Player : IComparable<Player>, IEquatable<Player>
  {
    public string Name { get; set; }
    public int Score { get; set; }

    public Player(string name)
    {
      Name = name;
      Score = 0;
    }

    public int CompareTo(Player other)
    {
      return Score.CompareTo(other.Score);
    }

    public static int ComparePlayersByScore(Player player1, Player player2)
    {
      if (player1.Score > player2.Score)
        return 1;
      else if (player1.Score < player2.Score)
        return -1;
      else
        return 0;
    }
  }

我需要做什么才能对这个列表进行排序并通过单元测试，以及为什么它是部分排序的。

Answer 1

您正在按升序 顺序对其进行排序，而不是降序...但是您的测试要求得分最高 的玩家排在第一位。这应该有效:

// Use the overload taking a Comparer<Player> delegate for simplicity
players.Sort((p1, p2) => p2.Score.CompareTo(p1.Score));

请注意在 lambda 表达式中反转使用 p1 和 p2 - 这就是反转比较的方式。