委托和泛型方法实现获得任意类型数组中的最大值

委托方式实现：

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

namespace 求任意数组的最大值
{
    class Program
    {
        delegate int CompareDelegate(object o1,object o2);

        static void Main(string[] args)
        {
            object[] array = new object[] {33,22,55,77,11};
            object max = GetMax(array,CompareInt);
            Console.WriteLine(max);

            object maxStr = GetMax(new object[] { "c", "bbbb", "aa" }, CompareString);
            Console.WriteLine(maxStr);

            Console.ReadKey();
        }

        static int CompareInt(object o1, object o2)
        {
            int n1 = Convert.ToInt32(o1);
            int n2 = Convert.ToInt32(o2);

            return n1 - n2;
        }

        static int CompareString(object s1,object s2)
        {
            string str1 = s1.ToString();
            string str2 = s2.ToString();

            return str1.Length - str2.Length;
        }

        static Object GetMax(object[] array,CompareDelegate del)
        {
            object max = array[0];
            for (int i = 1; i < array.Length; i++)
            {
                if (del(max,array[i])<0)
                {
                    max = array[i];
                }
            }
            return max;
        }

    }
}

 

泛型方法实现：（推荐）

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

namespace _02泛型方法实现任意数组的最大值
{
    delegate int GetMaxDeletate<T>(T t1, T t2);

    class Program
    {
        static void Main(string[] args)
        {
            int maxInt = GetMax<int>(new int[] { 3, 55, 11, 77, 333, 27 }, CompareInt);
            Console.WriteLine(maxInt);

            Person[] persons = { 
                            new Person(){Name="张三",Age =18},
                            new Person(){Name= "李四",Age= 55}
                            };

            Person maxPerson = GetMax<Person>(persons, ComparePerson);
            Console.WriteLine(maxPerson.Name);

            Console.ReadKey();
        }

        //比较数组的大小
        static int CompareInt(int i1, int i2)
        {
            return i1 - i2;
        }

        //比较Person对象的大小
        static int ComparePerson(Person p1, Person p2)
        {
            return p1.Age - p2.Age;
        }

        //T 起到占坑的作用 约束数据的类型
        static T GetMax<T>(T[] array, GetMaxDeletate<T> del)
        {
            T max = array[0];

            for (int i = 1; i < array.Length; i++)
            {
                if (del(max, array[i]) < 0)
                {
                    max = array[i];
                }
            }
            return max;
        }
    }

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

        public int Age { get; set; }

    }
}