C#自定义事件监听实现方法

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApp{ /// <summary> /// 定义事件 /// </summary> class CustomEvent {  /// <summary>  /// 定义委托  /// </summary>  /// <param name="sender"></param>  /// <param name="e"></param>  public delegate void UserRequest(object sender, EventArgs e);  /// <summary>  /// 此委托类型的事件  /// </summary>  public event UserRequest OnUserRequest;  public CustomEvent()  {   UserEventMonitor uem = new UserEventMonitor(this);  }  public void DoRun()  {   bool flag = false;   do   {    Console.WriteLine();    Console.WriteLine("请输入：");    string result = Console.ReadLine();    if (result == "1")    {     if (OnUserRequest != null)      OnUserRequest(this, new EventArgs());    }   } while (!flag);  } } /// <summary> /// 事件监听 /// </summary> class UserEventMonitor {  public UserEventMonitor(CustomEvent cem)  {   // cem.OnUserRequest += ShowMessage;   cem.OnUserRequest += delegate   {    Console.WriteLine("hello word!!");   };  }  public void ShowMessage(object sender, EventArgs e)  {   Console.WriteLine("hello word!!");  } } /// <summary> /// 调用类 /// </summary> public class Run {  static void Main(string[] args)  {   CustomEvent cem = new CustomEvent();   cem.DoRun();   Console.ReadLine();  } }}