Net核心:创建多列排序的表达式函数

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    public static void Main()
    {
        // 创建一个包含多个列的数据集合
        List<Person> people = new List<Person>
        {
            new Person { Name = "John", Age = 25 },
            new Person { Name = "Jane", Age = 30 },
            new Person { Name = "Alice", Age = 20 },
            new Person { Name = "Bob", Age = 25 }
        };

        // 定义排序规则
        Func<Person, object>[] sortExpressions = new Func<Person, object>[]
        {
            p => p.Age, // 按年龄排序
            p => p.Name // 按姓名排序
        };

        // 应用排序规则
        var sortedPeople = people.OrderBy(p => p, new MultiColumnComparer<Person>(sortExpressions));

        // 输出排序结果
        foreach (var person in sortedPeople)
        {
            Console.WriteLine($"Name: {person.Name}, Age: {person.Age}");
        }
    }
}

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public class MultiColumnComparer<T> : IComparer<T>
{
    private readonly Func<T, object>[] _expressions;

    public MultiColumnComparer(Func<T, object>[] expressions)
    {
        _expressions = expressions;
    }

    public int Compare(T x, T y)
    {
        foreach (var expression in _expressions)
        {
            var valueX = expression(x);
            var valueY = expression(y);

            var result = Comparer<object>.Default.Compare(valueX, valueY);
            if (result != 0)
            {
                return result;
            }
        }

        return 0;
    }
}