c#如何取得事件注册的方法 或者说 如何判断事件已经被注册过? ... ..

如何判断事件已经被注册过?

用反射取出事件绑定的委托实例，然后用GetInvocationList就可以得到所有注册的方法了

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Reflection;

namespace WindowsApplication19

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

            this.Load += new EventHandler(Form1_Load1);

            this.Load += new EventHandler(Form1_Load2);

            PropertyInfo propertyInfo = (typeof (Form)).GetProperty("Events", BindingFlags.Instance | BindingFlags .NonPublic);

            EventHandlerList eventHandlerList = (EventHandlerList)propertyInfo.GetValue(this , null );

            FieldInfo fieldInfo = ( typeof(Form)).GetField( "EVENT_LOAD", BindingFlags.Static | BindingFlags .NonPublic);

            Delegate d = eventHandlerList[fieldInfo.GetValue( null)];

            if (d != null)

            {

                foreach ( Delegate de in d.GetInvocationList())

                    Console.WriteLine(de.Method.Name);

            }

        }

        private void Form1_Load1( object sender, EventArgs e)

        {

            //什么也不干

        }

        private void Form1_Load2( object sender, EventArgs e)

        {

            //什么也不干

        }

    }

}