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C#笔记（十九）——委托和事件

2024-08-15 06:56:44   234人阅读

课堂练习
using System;
using System.Collections.Generic;
 
namespace Lesson13_3
{
 
                 //张三:初版按钮的实现
                 /*class Button
                {
                                
                                public string BtnName { get; set;}
 
                                public Button(string btnName){
                                                BtnName = btnName;
                                }
 
                                public void Onclick(){
                                                Console.WriteLine (BtnName+ "：被点击了");
                                                if (BtnName == "登录") {
                                                                LoginPageLogic logic = new LoginPageLogic ();
                                                                logic.Login ();
                                                } else if (BtnName == "取消") {
                                                                LoginPageLogic logic = new LoginPageLogic ();
                                                                logic.CancelLogin ();
                                                }
                                }
 
                                public void Onclick(Hero h){
                                                if (BtnName == "a1") {
                                                                h.LeftAction ();
                                                }
                                }
                }*/
                 //张三:委托版按钮的实现
                 class Button
                {
                                 //定义一个按钮委托
                                 public delegate void OnclickHandler ();
                                 //定义一个委托变量，用来存放点击操作的具体方法
                                 public OnclickHandler oncliAction;
 
                                 public void AddOnclickAction(OnclickHandler param){
                                                oncliAction = param;
                                }
 
                                 public string BtnName { get; set;}
 
                                 public Button(string btnName){
                                                BtnName = btnName;
                                }
 
                                 //按钮点击的时候调用的方法
                                 public void Onclick(Action< string> callBack){
                                                 Console.WriteLine (BtnName+ "：被点击了" );
 
                                                 if (oncliAction != null ) {
                                                                 //执行委托
                                                                oncliAction ();
                                                }
 
                                                 if (callBack != null ) {
                                                                callBack (BtnName);
                                                }
                                }
                }
 
                 //李四：登录页面逻辑
                 class LoginPageLogic {
                                 public void Login(){
                                                 Console.WriteLine ("登录成功" );
                                }
 
                                 public void CancelLogin(){
                                                 Console.WriteLine ("取消登录" );
                                }
                }
 
                 //王二： 英雄类
                 class Hero
                {
                                 public string HeroName{ get; set;}
 
                                 public void LeftAction(){
                                                 Console.WriteLine (HeroName+" 正在犀利的向左走位" );
                                }
 
                                 public void RightAction(){
                                                 Console.WriteLine (HeroName+" 正在犀利的向右走位" );
                                }
                }
 
                 class PrintTool {
                                 //定义一个判断字符串是否相等的方法委托
                                 public delegate bool StringIsEquals( string str1,string str2);
 
                                 public static void PrintIntArr( int[] arr){
                                                 foreach (int item in arr) {
                                                                 Console.WriteLine (item);
                                                }
                                }
                                 //判断两个字符串是否相等的方法
                                 public bool ArrayisEquals(string str1, string str2){
                                                 /*if (str1 == str2) {
                                                                return true;
                                                } else
                                                                return false;*/
                                                 return str1 == str2;
                                }
                }
 
                 class MainClass
                {
                                 public static void Main ( string[] args)
                                {
                                                 //委托的定义格式：
                                                 //访问修饰符  delegate 返回值类型 委托名称 (参数列表)
                                                 //访问修饰符           返回值类型 方法名称 (参数列表)
 
                                                 //委托的用法：
                                                 //1、声明委托
                                                 VoidFunction action;
                                                 //2、绑定委托
                                                 //   1.直接赋值
                                                 //action = EngGreeting;
                                                 //   2.通过new关键字来初始化绑定
                                                action = new VoidFunction (EngGreeting);
                                                 //3、调用（和方法的调用类似）
                                                 //action ("张三");
                                                 //4、多播委托，可以将多个方法通过+=运算符绑定到一个委托上
                                                 //   调用委托的时候，会将委托上绑定的方法分别执行
                                                action += ChineseGreeting;
                                                action ("李四" );
 
                                                 //1、绑定实例对象的方法
                                                 /*PrintTool print = new PrintTool ();
                                                //声明委托
                                                Print printArr = new Print (print.PrintIntArr);
                                                int[] result = new int[6]{ 1,2,3,4,5,6};
                                                printArr (result);*/
 
                                                 //2、
                                                 int[] arr = new int[5]{ 1,2,3,4,5};
                                                 Print printArr = new Print ( PrintTool.PrintIntArr);
                                                printArr (arr);
 
                                                 PrintTool tool = new PrintTool ();
                                                 PrintTool.StringIsEquals isEquals = new PrintTool. StringIsEquals (tool.ArrayisEquals);
                                                 bool result = isEquals ("a" ,"a");
                                                 Console.WriteLine (result);
 
                                                 List<int > arrlist = new List< int> ();
                                                arrlist.Add (2);
                                                arrlist.Add (1);
                                                arrlist.Add (5);
                                                arrlist.Add (3);
                                                arrlist.Sort ();
                                                 foreach (var item in arrlist) {
                                                                 Console.WriteLine (item);
                                                }
                                                 Console.Clear ();
 
                                                 //合并委托： 如果委托有返回值，那么返回值就是最后绑定的方法的返回值
                                                 Addelegate del = Add;
                                                del += Mul;
                                                 int result1 = del (2,3);
                                                 Console.WriteLine (result1);
 
                                                 //解除绑定：注意委托不能为null
                                                del -= Mul;
                                                del -= Mul;
                                                 //del -= Add;
                                                 Console.WriteLine (del(2,3));
 
                                                 //登录，取消页面逻辑
                                                 LoginPageLogic page = new LoginPageLogic ();
 
                                                 //登录按钮
                                                 Button loginBtn = new Button ( "登录");
                                                 //为登录按钮绑定登录逻辑
                                                loginBtn.AddOnclickAction (page.Login);
                                                loginBtn.Onclick (delegate(string message){
                                                                 Console.WriteLine (message);
                                                });
 
                                                 //为取消按钮绑定取消登录的逻辑
                                                 Button cancelBtn = new Button ( "取消");
                                                cancelBtn.oncliAction = page.CancelLogin;
                                                cancelBtn.Onclick (null);
 
 
                                                 Hero dema = new Hero ();
                                                dema.HeroName = "德玛西亚" ;
                                                 //向左操作按钮
                                                 Button leftBtn = new Button ( "a1");
                                                leftBtn.oncliAction = dema.LeftAction;
                                                leftBtn.Onclick (null);
                                                 //s向左操作按钮
                                                 Button rightBtn = new Button ( "d1");
                                                rightBtn.oncliAction = dema.RightAction;
 
                                                 //匿名方法1、无返回值的匿名方法：delegate(参数列表){ 方法体 }2、有返回值的匿名方法：delegate(int x,int y){return x+y}3、在将匿名方法赋值给委托的时候，末尾的 ; 不能忘
                                                 Addelegate delAdd = delegate (int x, int y) {
                                                                 return x + y;
                                                };
 
                                                 //2、lambda表达式：
                                                delAdd = (int x,int y) => {
                                                                 return x*y;
                                                };
                                                 Console.WriteLine (delAdd (4,5));
 
                                                 //Func:范型委托
                                                 Func<int ,int ,string, float> chu = (int x,int y,string name) => {
                                                                 Console.WriteLine (name);
                                                                 return x+y;
                                                };
 
                                                 Console.WriteLine (chu(3,5,"张三" ));
                                }
 
                                 //定义打印数组的委托
 
                                 public delegate int Addelegate( int x,int y);
 
                                 public delegate void Print(int[] arr);
                                 public delegate void VoidFunction( string _n);
 
                                 public static   void ChineseGreeting( string name){
                                                 Console.WriteLine ("早上好：" +name);
                                }
 
                                 public static void EngGreeting( string name){
                                                 Console.WriteLine ("good morning:" +name);
                                }
 
                                 public static int Add( int x,int y){
                                                 return x + y;
                                }
 
                                 public static int Mul( int x,int y){
                                                 return x * y;
                                }
                }
}
//================================================================
using System;
 
namespace Lesson13_2
{
 
                 public class Person{
                                 public string name;
 
                                 public void Congratulate(){
                                                 Console.WriteLine (this .name+" 祝贺新郎新娘百年好合～！" );
                                }
                }
 
                 public class Button{
                                 public string btnName;
                                 //事件的
                                 public delegate void OnclickHandler();
                                 public event OnclickHandler ClickEvent;
 
                                 public void AddClickListener(OnclickHandler clickCall){
                                                ClickEvent += new OnclickHandler (clickCall);
                                }
 
                                 public void Onclick(){
                                                 if (ClickEvent != null ) {
                                                                ClickEvent ();
                                                }
                                }
                }
 
                 public class CJBoy{
 
                                 public delegate void MarryHandle();
                                 //事件的发起者
                                 public event MarryHandle marryEvent;
                                
                                 public void SayLove(string qs){
                                                 Console.WriteLine ("黑负泪" );
                                }
 
                                 public void XYQ(){
                                                 Console.WriteLine ("送玫瑰" );
                                }
 
                                 public void Song(){
                                                 Console.WriteLine ("你笑的多甜蜜蜜蜜" );
                                }
 
                                 public bool Ask(string name){
                                                 Console.WriteLine ("你到底接不接受" );
                                                 return true ;
                                }
 
                                 public long PhoneNum(){
                                                 return 133010556;
                                }
 
                                 public void SendMessage(Action callback){
                                                 if (callback != null ) {
                                                                callback ();
                                                }
                                }
 
                                 //给事件添加一个监听
                                 public void AddMarryListener(MarryHandle listener){
                                                marryEvent += new MarryHandle (listener);
                                }
 
                                 public void Marry(){
                                                 Console.WriteLine ("要结婚了" );
                                                 //事件触发
                                                 if (marryEvent != null ) {
                                                                marryEvent ();
                                                }
                                }
                }
                 //delegate bool AskHandle();
                 //delegate bool AskHandle(string name);
 
 
 
                 class MainClass
                {
                                 public static void Main ( string[] args)
                                {
                                                 CJBoy boy = new CJBoy ();
 
                                                 //Func：用于创建有返回值类型的委托，
                                                 //注意，返回值一定义是最后那个参数
                                                 Func<string ,bool> laowang
                                                                = new Func <string, bool> (boy.Ask);
                                                 bool result = laowang ("超级男孩" );
                                                 Console.WriteLine (result);
 
                                                 Func<long > laowang2 = new Func< long> (boy.PhoneNum);
                                                 Console.WriteLine (laowang2 ());
 
                                                 //Action: 用于创建没有返回值类型的委托
                                                 Action<string > laowang3
                                                = new Action <string> (boy.SayLove);
                                                laowang3 ("流浪" );
 
                                                 Action laowang4 = new Action (boy.Song);
                                                laowang4 ();
 
                                                boy.SendMessage (delegate(){
                                                                 Console.WriteLine ("吃饭了吗～！" );
                                                });
 
                                                 Person plaowang = new Person();
                                                plaowang.name = "老王" ;
                                                 Person p2 = new Person();
                                                p2.name = "老张" ;
                                                 Person p3 = new Person();
                                                p3.name = "老李" ;
 
                                                boy.AddMarryListener (plaowang.Congratulate);
                                                boy.AddMarryListener (p2.Congratulate);
                                                boy.AddMarryListener (p3.Congratulate);
 
                                                 //结婚当天
                                                boy.Marry ();
 
                                                 //
                                                 Button loginBtn = new Button ();
                                                loginBtn.AddClickListener (delegate(){
                                                                 Console.WriteLine ("登陆" );
                                                });
 
                                                 Button cancelBtn = new Button ();
                                                cancelBtn.AddClickListener (delegate(){
                                                                 Console.WriteLine ("取消登陆" );
                                                });
 
                                                 Button skill1Btn = new Button ();
                                                skill1Btn.AddClickListener (delegate(){
                                                                 Console.WriteLine ("大招" );
                                                });
 
                                                loginBtn.Onclick ();
 
                                                cancelBtn.Onclick ();
 
                                                skill1Btn.Onclick ();
                                }
                }
}
 

C#笔记（十九）——委托和事件


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