根据字典的值对字典的键进行排序；值表示数组，排序顺序不同 - 升序/降序； C＃

Question

我想对对象列表进行排序。结构是Dictionary<object, double[]>，如下所示：

    Dictionary<int, double[]> dict = new Dictionary<int, double[]>{
    {object1, new double[]{0.02, 0.10, 0.30, 0.5}},
    {object4, new double[]{0.02, 0.10, 0.30, 0.2}},
    {object3, new double[]{0.02, 0.10, 0.30, 0.3}},
    {object2, new double[]{0.02, 0.10, 0.50, 0.4}}
    };

数组应该根据索引以不同的顺序排列。即第一个、第二个和第四个索引升序，第三个索引降序。所以最终，我应该得到：

object2, 0.02, 0.1, 0.5, 0.4
object4, 0.02, 0.1, 0.3, 0.2
object3, 0.02, 0.1, 0.3, 0.3
object1, 0.02, 0.1, 0.3, 0.5

我使用发布在here 的代码作为起点。我应该做什么样的调整？当然，我知道该方法将不再是通用的（数组长度无关）。我正在考虑创建一个与double[] 大小相同的bool[]，其中True 代表升序排序，False 代表降序，但比较方法严格获取2 个参数。任何帮助将非常感激。谢谢！

Answer 1

您可以使用 Linq 库。在字典上调用OrderBy。

var x = dict.OrderBy(o => o.Value[0]).ThenBy(o => o.Value[1]).ThenBy(o => -o.Value[2]).ThenBy(o => o.Value[3]);

完整代码：

using System.Linq;
...........
public static void Main()
    {
        var object1 = 1;
        var object2 = 2;
        var object3 = 3;
        var object4 = 4;
        
        Dictionary<int, double[]> dict = new Dictionary<int, double[]>{
        {object1, new double[]{0.02, 0.10, 0.30, 0.5}},
        {object4, new double[]{0.02, 0.10, 0.30, 0.2}},
        {object3, new double[]{0.02, 0.10, 0.30, 0.3}},
        {object2, new double[]{0.02, 0.10, 0.50, 0.4}}
        };
        
        var x = dict.OrderBy(o => o.Value[0]).ThenBy(o => o.Value[1]).ThenBy(o => -o.Value[2]).ThenBy(o => o.Value[3]);
        
        // write ordered values
        foreach (var d in x)
        {
            Console.Write(d.Key + ", [");
            foreach (var v in d.Value)
                Console.Write(v + ", ");
            Console.WriteLine("]");
        }
    }

输出

2, [0.02, 0.1, 0.5, 0.4, ]
4, [0.02, 0.1, 0.3, 0.2, ]
3, [0.02, 0.1, 0.3, 0.3, ]
1, [0.02, 0.1, 0.3, 0.5, ]

Answer 2

如果我没听错，请尝试使用此比较器：

    public class SequenceComparer : IComparer<IList<double>>
    {
        public SequenceComparer(bool[] markers)
        {
            Markers = markers;
        }

        public bool[] Markers { get; }
        
        public int Compare(IList<double> x, IList<double> y)
        {
            //check for null
            if (x == null || y == null || Markers == null)
            {
                throw new Exception("Null arrays are not valid");
            }

            //check identical count
            if (x.Count != y.Count || x.Count != Markers.Length)
            {
                throw new Exception("Invalid count");
            }

            for (var i = 0; i < x.Count; i++)
            {
                if (x[i].Equals(y[i]))
                {
                   continue;
                }

                var comparisonResult = x[i] > y[i] ? 1 : -1;
                
                //if marker is false, invert comparisonResult
                return Markers[i] ? comparisonResult : comparisonResult * -1;
            }

            //Your arrays are identical, just skip
            return 1;
        }
    }

您可以使用任意长度的数组并使用bool[] 标志来调整排序方向
使用示例：

var query = dict.OrderBy(pair => pair.Value, new SequenceComparer(new []{true, true, false, true}));