【C#】学习笔记(3) 关于Events使用的小Demo

关于Events事件的简单Demo.

目录结构：

Program.cs

 using System;
 namespace EventsDemo
 {
     class Program
     {
         static void Main(string[] args)
         {
             Book book = new Book();
             book.BookAdded += OnBookAdded;
             book.AddBook("One");
             book.BookAdded -= OnBookAdded;
             book.AddBook("Two");
             book.BookAdded += OnBookAdded;
             book.AddBook("Three");
             book.BookAdded -= OnBookAdded;
             book.AddBook("Four");
         }
         static void OnBookAdded(object sender, EventArgs args)
         {
             System.Console.WriteLine("A book was added");
         }
     }
 }

Book.cs

 using System;
 namespace EventsDemo
 {
     public delegate void BookAddedDelegate(object sender, EventArgs args);
     class Book
     {
         public void AddBook(string bookname)
         {
             if (BookAdded != null)
             {
                 BookAdded(this, new EventArgs());
                 System.Console.WriteLine($"BookName:{bookname}");
             }
         }
         public event BookAddedDelegate BookAdded;
     }
 }

输出：