活动是代表，我需要一个小例子来了解所有内容 [英] Events are delegates, i need a small example to understand everything

问题描述

能给我一个小例子，说明我们如何使用事件以及如何将委托一起使用，
在其中有EventHandler的地方，我们在其中引发事件并对其进行处理.
请给我一个小例子，并逐步说明.
我已经读了很多书，但是找不到一个很好的例子来理解一切工作原理.

Can you give me a small example how we used events, and delegates together,
something where there is EventHandler, where we raise the event and handle it.
Please give me a small example and explain it step by step.
I have read a lot, but cant find a good example to understand how everything works

推荐答案

我过去曾经问过这个问题.
阅读此 [

I asked this question once in the past.
Read this[^] question and solution 1!

Handler 是在Event之后被调用的方法.
Delegate 是指向Handler的点.
Delegate 指定Handler数据类型及其参数名称和参数数据类型.

Handler is a method that is being called after the Event.
Delegate is a point to the Handler.
Delegate specifies Handler data type and it''s parameters names and parameters data types.

public class Person
{
    private static Random random = new Random();

    private string[] words = new string[10] { "I am talking", "Good", "Oh!", "Wow!", "No.", "Bingo", "Wait a second", "I'm busy right now.", "LOL", "What?" };

    public string Name { get; set; }

    public void Say(Person addressee)
    {
        System.Threading.Thread.Sleep(500);

        if(onSay!= null)
            onSay(this, words[random.Next(0, 9)]);

        addressee.Say(this);
    }

    public delegate void SayHandler(Person sender, string word);
    public SayHandler onSay;
}

在简单控制台应用程序中进行测试:

For testing in a Simple Console Application:

class Program
{
    static void Main(string[] args)
    {
        Person person1 = new Person()
        {
            Name = "John"
        };

        Person person2 = new Person()
        {
            Name = "Bill"
        };

        person1.onSay += new Person.SayHandler(SomeBodySay);//It determines that SomeBodySay method must be call after calling onSay method. For person1

        person2.onSay += new Person.SayHandler(SomeBodySay);

        person1.Say(person2);

        Console.ReadKey();
    }


    static void SomeBodySay(Person person, string word)
    {
        Console.WriteLine("{0} said: {1}", person.Name, word);
    }

而且这可能会有所帮助:

C#中的事件和事件处理 [

And also this may helps:

Events and event handling in C#[^]

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