.Net Framework中的标准委托，已经定义在命名空间System中，
namespace System{ public delegate void EventHandler(object sender, EventArgs e);}.Net Framwork类库中的所有事件均基于EventHandler委托。
其中EventArgs参数是可以自定义，必须继承EventArgs类：
public class CustomEventArgs:EventArgs
发布事件有三种方式：
1. 使用.net framework标准委托
public event EventHandler RaiseCustomEvent;
2. 自定义EventArgs参数
public event CustomEventHandler RaiseCustomEvent;
3. 自定义EventArgs参数，泛型的表达方式
public event EventHandler<CustomEventArgs> RaiseCustomEvent;
如何：发布符合.net framework准则的事件
首先分两个类：
1. 发行者类（Publisher），发送Sends（引发Raise）事件的类，这个类做两件事
窗体（Form）和控件（control）的类中都发布了事件（Load，Click等），事件的触发程序被封装了。
2. 订阅者类（Subscriber），接收Receive（处理Handle）事件的类，这个类做两件事
当你双击Form1中的一个按钮Button1，会直接进入
private void button1_Click(object sender, EventArgs e) { } 其实就是在写事件的处理程序；在Form1.Designer.cs中会自动注册按钮双击事件
this.button1.Click += new System.EventHandler(this.button1_Click);
下面来看一个例子，是一个比较标准的方式添加自定义的事件：
namespace DotNetEvents{ class Program { static void Main(string[] args) { Publisher pub = new Publisher(); Subscriber sub1 = new Subscriber("sub1", pub); Subscriber sub2 = new Subscriber("sub2", pub); //Call the method that raises the event pub.DoSomething(); Console.WriteLine("Press Enter to close this window."); Console.ReadKey(); } } //Define a class to hold custom event info public class CustomEventArgs:EventArgs { private string message; public CustomEventArgs (string s) { message = s; } public string Message { get { return message;} set { message = value; } } } //Class that publishes an event class Publisher { //Declare the event using EventHandler<T> public event EventHandler<CustomEventArgs> RaiseCustomEvent; public void DoSomething() { //Write some code that does something useful here //then raise the event.You can also raise an event //before you execute a block of code. OnRaiseCustomEvent(new CustomEventArgs("Did something")); } //Wrap event invocations inside a protected virtual method //to allow derived classes to oveeride the event invocation behavior protected virtual void OnRaiseCustomEvent(CustomEventArgs e) { //Make a temporary copy of the event to avoid possibility of //a race condition if the last subscriber unsubscribes //immediately after the null check and before the event is raise if(RaiseCustomEvent !=null ) { e.Message = String.Format(" at {0}", DateTime.Now.ToString()); RaiseCustomEvent(this, e); } } } //Class that subscribes to an event class Subscriber { private string id; public Subscriber (string ID,Publisher pub) { id = ID; //Subscribe to the event suing C# 2.0 syntax pub.RaiseCustomEvent += HandleCustomEvent; } //Define what action to take when the event is raised void HandleCustomEvent(object sender,CustomEventArgs e) { Console.WriteLine(id + " receive this message: {0}", e.Message); } }}
原标题：.Net Framework中的标准委托和事件_1
关键词：.NET
我知道了 