using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace UserControls
{
    public partial class UserControl1 : UserControl
    {
        public delegate void MyDelegate(object sender, EventArgs e);//建立委托
        public MyDelegate myEven_click;
        public UserControl1()
        {
            InitializeComponent();
            button1.Click += new EventHandler(button1_Click); //绑定委托事件
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (myEven_click != null)
            {
                myEven_click(sender, e);
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace 自定义控件的点击事件
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            userControl11.myEven_click += new UserControls.UserControl1.MyDelegate(fuzhi);//把事件绑定到自定义的委托上
        }
        public void fuzhi(object sender ,EventArgs e)
        {
            label1.Text = "456";
        }
    }
}