c#如何取得事件注冊的方法

這個問題來自論壇，原文為如何判斷事件已經被注冊過?

用反射取出事件綁定的委托實例，然後用GetInvocationList就可以得到所有注冊的方法了。

代碼

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01.using System;
02.using System.Collections.Generic;
03.using System.ComponentModel;
04.using System.Data;
05.using System.Drawing;
06.using System.Text;
07.using System.Windows.Forms;
08.using System.Reflection;
09.namespace WindowsApplication19
10.{
11.    public partial class Form1 : Form
12.    {
13.        public Form1()
14.        {
15.            InitializeComponent();
16.
17.            this.Load+=new EventHandler(Form1_Load1);
18.            this.Load+=new EventHandler(Form1_Load2);
19.
20.            PropertyInfo propertyInfo = (typeof(Form)).GetProperty("Events", BindingFlags.Instance | BindingFlags.NonPublic);
21.            EventHandlerList eventHandlerList = (EventHandlerList)propertyInfo.GetValue(this, null);
22.            FieldInfo fieldInfo = (typeof(Form)).GetFIEld("EVENT_LOAD", BindingFlags.Static | BindingFlags.NonPublic);
23.
24.            Delegate d = eventHandlerList[fIEldInfo.GetValue(null)];
25.
26.            if (d != null)
27.            {
28.                foreach (Delegate de in d.GetInvocationList())
29.                    Console.WriteLine(de.Method.Name);
30.            }
31.        }
32.        private void Form1_Load1(object sender, EventArgs e)
33.        {
34.            //什麼也不干
35.        }
36.        private void Form1_Load2(object sender, EventArgs e)
37.        {
38.            //什麼也不干
39.        }
40.    }
41.}