事件是C#中一个重要的内容，MSDN上有一个自定义事件的演示示例。我看了半天有点晕，所以新建了一个winform工程添加了一个按钮，然后找出调用的程序，一对比做了一个类似的示例，就明白了。看代码有时候比看文档来得更快。

using System;
 
namespace TestEventArgs
{
    /// <summary>
    /// 这个类对应于EventArgs，做对比学习。
    /// 添加两个内容：info1，info2。
    /// </summary>
    public class MyEventArgs : EventArgs
    {
        private String info1;
        private UInt32 info2;
 
        public MyEventArgs(String info1, UInt32 info2)
        {
            this.info1 = info1;
            this.info2 = info2;
        }
 
        public String Info1
        {
            get { return this.info1; }
            set { this.info1 = value; }
        }
 
        public UInt32 Info2
        {
            get { return this.info2; }
            set { this.info2 = value; }
        }
    }
 
    /// <summary>
    /// 仿真Button按钮
    /// </summary>
    public class MyButton
    {
        public delegate void MyEvnetHandler(object sender, MyEventArgs e);
        /// <summary>
        /// 按钮点击的次数计数器
        /// </summary>
        public static UInt32 clicked_num = 0;
        public event MyEvnetHandler MyClick;
 
        public void 触发()
        {
            MyEventArgs arg = new MyEventArgs(DateTime.UtcNow.ToString(), ++clicked_num);
            MyClick(this, arg);
        }
    }
 
    /// <summary>
    /// 仿真Form窗体
    /// </summary>
    public class MyForm
    {
        public MyButton 按钮;
        public MyForm()
        {
            按钮 = new MyButton();
            按钮.MyClick += new MyButton.MyEvnetHandler(this.button_Clicked);
        }
 
 
        public void button_Clicked(object sender, MyEventArgs e)
        {
            Console.WriteLine("button clicked(sender is:" + sender.ToString() + "; info1 = "
                + e.Info1 + "; info2 = " + e.Info2);
        }
    }
 
    class Program
    {
        static void Main(string[] args)
        {
            MyForm 窗体 = new MyForm();
            for (int i = 0; i < 10; i++ )
            {
                窗体.按钮.触发();
                System.Threading.Thread.Sleep(500);
            }
            Console.WriteLine("Press any key to continue...");
            Console.ReadKey();
        }
    }
}

不同的地方：
1 本示例中delegate myevnethandler是mybutton类内部成员，在系统中eventhander是system命名空间下的一个成员。