学委托必懂的例子

此例子采用委托来排序,整体思路如下:

建一Sorter类,用意是对所有的对象数组排序,不论这个对象是什么类型,只要它满足了Sorter类中的带的一个委托即可,然后新建一个员工类,用这个Sorter类来对一堆员工的工资进行排序.

好了,第一步,新建Sorter类:

 

 1using System;
 2using System.Collections.Generic;
 3using System.Text;
 4
 5namespace BubbleSorter2
 6{
 7    class Sorter
 8    {
 9        // 参数内的对象比较的方法
        public delegate bool IsGreater(object a,object b);
        // 采用冒泡比较的方法对对象数组内的对象进行比较
        public static void Sort(object[] objs, IsGreater Compare)
        {
            for (int i = 0; i < objs.Length-1; i++)
            {
                bool flag = false;
                object temp;
                if (!flag)
                {
                    for (int j = objs.Length - 1; j > i; j--)
                    {
                        if (!Compare(objs[j], objs[j - 1]))
                        {
                            temp = objs[j - 1];
                            objs[j - 1] = objs[j];
                            objs[j] = temp;
                        }
                        flag = true;
                    }
                }
            }
        }
    }
}

 

第二步,新建员工类:

 

 

 1using System;
 2using System.Collections.Generic;
 3using System.Text;
 4
 5namespace BubbleSorter2
 6{
 7    class Employee
 8    {
 9        private string name;
        private decimal salary;

        public Employee(string par_name,decimal par_salary)
        {
            name = par_name;
            salary = par_salary;
        }
        public string Name
        {
            get
            {
                return this.name;
            }
            set
            {
                name = value;
            }
        }
        public decimal Salary
        {
            get
            {
                return salary;
            }
            set
            {
                salary = value;
            }
        }

        // 这里满足了Sorter类要求的排序委托,也就是提供一个比较两个员工工资的方法
        public static bool IsGeater(object a, object b)
        {
            if (((Employee)a).salary >= ((Employee)b).salary)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}

 

最后在主函数内进行调用

 

 1using System;
 2using System.Collections.Generic;
 3using System.Text;
 4using System.Collections;
 5
 6namespace BubbleSorter2
 7{
 8    class Program
 9    {
        static void Main(string[] args)
        {
            // 这里用代码新建几个员工
            Employee[] employees =
                {
                    new Employee("Mr a",40000),
                    new Employee("Miss b",5000),
                    new Employee("Mrs c",10000),
                    new Employee("BOSS d",4000000),
                    new Employee("Sir e",300000),
                    new Employee("boy f",444444)                
                };

            PrintValues(employees);
            Sorter.Sort(employees, Employee.IsGeater);
            PrintValues(employees);

            Console.ReadKey();
        }

        public static void PrintValues(IEnumerable myList)
        {
            foreach (object obj in myList)
            {
                Console.WriteLine("{0}", ((Employee)obj).Salary);
            }
            Console.WriteLine();
        }
    }
}

 

大功告成.