.net学习之委托和事件

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

namespace ConsoleApplication1
{
    public delegate void DGEach(int index,object item);
    public delegate void DGTest();

    internal class Program
    {
        public static void Test1(DGTest dgTest)
        {
            dgTest(); //编译后：dgTest.Invoke();
            Console.WriteLine("Test1");
        }

        public static void Test2()
        {
            Console.WriteLine("Test2");
        }

        public static void Test3()
        {
            Console.WriteLine("Test3");
        }

        /// <summary>
        /// 委托当返回值
        /// </summary>
        /// <param name="strType"></param>
        /// <returns></returns>
        public static DGTest InvokeTest(string strType)
        {
            switch (strType)
            {
                case "2":
                    return Test2;
                case "3":
                    return Test3;
                default:
                    return Test3;
            }
        }

        /// <summary>
        /// 使用委托模仿jQuery each方法
        /// </summary>
        /// <param name="list"></param>
        /// <param name="func"></param>
        public static void Each(ArrayList list, DGEach func)
        {
            for (int i = 0; i < list.Count; i++)
            {
                func(i, list[i]);
            }
        }

        private static void Main(string[] args)
        {
            #region 委托当参数

            //DGTest dgTest = new DGTest(Test2);//或者    DGTest dgTest  = Test2;
            //Test1(dgTest);

            #endregion

            #region  委托当返回值

            //DGTest dgTest = InvokeTest("2");
            //dgTest();

            #endregion

            #region 完成 Each方法

            //ArrayList list = new ArrayList();
            //list.Add("刘德华");
            //list.Add("张学友");
            //list.Add("郭富城");
            //list.Add("黎明");
            // Each(list, delegate(int index,object item)
            // {
            //     Console.WriteLine(index+"---------"+item.ToString());
            // });

            #endregion

            #region 事件练习,一个设计模式的题目，说有三个对象，猫，老鼠，人，猫看见了老鼠，老鼠吓跑了，在过程中把人吵醒， 在编程过程中注意新的对象的参与
            Cat c = new Cat();
            c.Name = "tom";
            c.DGRunEventHandler += c_DGRunEventHandler;
            c.SeeMouse(c.Name);
            #endregion
        }

        private static void c_DGRunEventHandler(object sender,EventArgs e)
        {
            Mouse m = new Mouse();
            m.Name = "mouse1";
            m.DGRunEventHandler += m_DGRunEventHandler;
            m.MouseRun(m);
        }

        private static void m_DGRunEventHandler(object sender, EventArgs e)
        {
            Person p = new Person();
            p.WakeUp(sender);
        }
    }


        public class Cat
        {
           public event EventHandler DGRunEventHandler;
            public void SeeMouse(string name)
            {
                Console.WriteLine(name+"看见老鼠");
                if (DGRunEventHandler != null)
                {
                    DGRunEventHandler(this,new EventArgs());
                }
            }

            public  string Name { get; set; }
        }
        public class Person
        {
            public void WakeUp(object sender)
            {

                 Console.WriteLine((sender as Mouse).Name+"老鼠跑,人醒了");
            }
            public string Name { get; set; }
        }

        public class Mouse
        {
            public event EventHandler DGRunEventHandler;
            public void MouseRun(object sender)
            {
                Console.WriteLine((sender as Mouse).Name+"老鼠跑");
                if (DGRunEventHandler != null)
                {
                    DGRunEventHandler(this, new EventArgs());
                }
            }
            public string Name { get; set; }
        }
}