C#学习（面向对象）Day12——委托、匿名函数、回调、事件

1.委托（Action,Func)

using System;namespace bDelegate
{//委托-----------------------------------------------------//别名：句柄、代理//自定义类型、引用类型//就是来存储方法的结构//delegate 返回值类型 委托类型名（参数列表）；//委托对象-------------------------------------------------//[访问修饰符] 委托类型名称 委托对象的名称；//给委托对象赋值//委托对象 = 方法名;//xiaoming.buyHoueEventHandle = intermediary.BuyHouse;（注意只写方法名，没有括号）//ips：委托对象，保存的是方法的内存地址//public BuyHouseEventHandle buyHouseEventHandle;//委托对象的绑定与解绑定//xiaoming.buyHoueEventHandle += lianjia.BuyHouse;//xiaoming.buyHoueEventHandle -= lianjia.BuyHouse;//委托对象的执行//委托对象(参数列表);//House house = xiaoming.buyHoueEventHandle(1000000,80);//Tips：委托对象为空是不能执行的，执行前先提前判断public class ActionAndFunc{//无返回值无参private Action testAction;//无返回值有参private Action<float> floatAction;private Action<float, int> floatIntAction;//有返回值有参private Func<int> returnIntFunc;private Func<int, float> newFunc;void Bind(){Action<int, float, string> test1Action = Test1;Func<int, Apartment> test2Func = Test2;test2Func += Test2;test2Func = Test2;}Apartment Test2(int money){return null;}void Test1(int a, float b, string c){}}
}

2.匿名函数（普通方式，拉姆达表达式）

using System;namespace bDelegate
{//匿名函数//匿名函数就是没有函数名的函数//匿名函数仅限委托绑定public class Hero{private byte age;public string name;public Action<Hero> attack;public Hero(string name){this.name = name;}public byte Age{get => age;set => age = value;}}public class AnonymousMethod{public static void Demo(){Hero akl = new Hero("阿卡丽");akl.attack = TestAttack;//匿名方法绑定akl.attack += delegate(Hero hero){Console.WriteLine(hero.name + "正在被攻击...");};//拉姆达表达式的方式绑定akl.attack += hero =>{Console.WriteLine(hero.name + "正在被攻击...");};akl.attack(new Hero("提莫"));}public static void TestAttack(Hero hero){Console.WriteLine(hero.name + "正在被攻击...");}}
}

3.回调

using System;namespace bDelegate
{//回调public class CallbackDemo{public void Doit(){PrintNumbers(SayHello);}//Action aGoodThing = SayHello;private void PrintNumbers(Action aGoodThing){for (int i = 0; i < 100; i++){Console.WriteLine(i + 1);}aGoodThing();}private void SayHello(){Console.WriteLine("Hello");}}public class Monster{public void TakeDamage(float damage){}}
}

4.事件

using System;namespace bDelegate
{//事件//特殊的委托对象//在非事件所在的类中，只能对事件进行绑定（+=）和解绑定（-=）//在事件所在的类中，可以对事件进行赋值（=）、调用、绑定（+=）和解绑定（-=）public delegate void MyEventHandle(float a, int b);public class OtherClass{public void Test(){EventDemo demo = new EventDemo();demo._myEventHandle += ShowNumbers;demo._myEventHandle -= demo.MyFunction;}public void ShowNumbers(float a, int b){}}public class EventDemo{//        委托类型        委托对象public event MyEventHandle _myEventHandle;void Demo(){_myEventHandle = (f, i) => { };_myEventHandle += (f, i) =>{Console.WriteLine("Hello");};_myEventHandle = MyFunction;}public void MyFunction(float a, int b){}}
}

4.作业

创建?板类，设计字典存储?板的所有资源

资源内容包括：

潘?屹：可以提供免费的办公场所

?云：可以提供低价的货源

雷军：可以提供销售能?极强的员?

通过委托回调建?这些联系

完成?板开?卖货的功能

using System;
using System.Collections.Generic;namespace test1
{class Boss{public delegate void SaleGoods();public static void Main(string[] args){SaleGoods test = new SaleGoods(Resouce.FreeRoom);test += Resouce.LowerPriceGood;test += Resouce.SaleStaff;test();}}public class Resouce{public static void FreeRoom(){Console.WriteLine("提供了免费的办公场所...");}public static void LowerPriceGood(){Console.WriteLine("提供了低价的货物...");}public static void SaleStaff(){Console.WriteLine("提供了销售能力极强的工作人员...");}}}