在方法中使用Predicate<T>或Func<T>进行过滤

using System;
using System.Collections.Generic;

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

public class Program
{
    public static void Main()
    {
        List<Person> people = new List<Person>
        {
            new Person { Name = "Alice", Age = 30 },
            new Person { Name = "Bob", Age = 25 },
            new Person { Name = "Charlie", Age = 35 }
        };

        Predicate<Person> isAdult = p => p.Age >= 30;
        List<Person> adults = people.FindAll(isAdult);

        foreach (var person in adults)
        {
            Console.WriteLine($"{person.Name} is an adult.");
        }
    }
}

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

public class Program
{
    public static void Main()
    {
        List<int> numbers = new List<int> { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

        Func<int, bool> isEven = n => n % 2 == 0;
        var evenNumbers = numbers.Where(isEven).ToList();

        foreach (var number in evenNumbers)
        {
            Console.WriteLine($"{number} is even.");
        }
    }
}

var evenNumbersParallel = numbers.AsParallel().Where(isEven).ToList();