C# 中数组比较作为字典键

csharp
using System;
using System.Collections.Generic;
public class ArrayComparer : IEqualityComparer
{
    public bool Equals(T[] x, T[] y)
    {
        if (x == null || y == null)
            return false;
        if (x.Length != y.Length)
            return false;
        for (int i = 0; i < x.Length; i++)
        {
            if (!EqualityComparer.Default.Equals(x[i], y[i]))
                return false;
        }
        return true;
    }
    public int GetHashCode(T[] obj)
    {
        unchecked
        {
            int hash = 17;
            foreach (var item in obj)
            {
                hash = hash * 23 + (item?.GetHashCode() ?? 0);
            }
            return hash;
        }
    }
}

csharp
using System;
using System.Collections.Generic;
class Program
{
    static void Main()
    {
        // 使用自定义比较器
        var arrayComparer = new ArrayComparer();
        // 创建字典并指定比较器
        var dictionary = new Dictionary(arrayComparer);
        // 添加带有数组键的项
        int[] key1 = { 1, 2, 3 };
        dictionary[key1] = "Value1";
        int[] key2 = { 4, 5, 6 };
        dictionary[key2] = "Value2";
        // 尝试使用相同的数组作为键来检索值
        int[] keyToLookup = { 1, 2, 3 };
        if (dictionary.TryGetValue(keyToLookup, out var result))
        {
            Console.WriteLine($"The value for key {string.Join(", ", keyToLookup)} is: {result}");
        }
        else
        {
            Console.WriteLine("Key not found.");
        }
    }
}