【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：