1）使用者控制元件UserControl1.cs

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 WindowsFormsApplication28
{
    public partial class UserControl1 : UserControl
    {
        private Button btnTest = new Button();
        //定義事件
        public delegate void MyDelegate(object sender, EventArgs e);
        public event MyDelegate myEvent;
        public UserControl1()
        {
            InitializeComponent();
            //button
            btnTest.Text = "test";
            btnTest.Location = new Point(1, 1);
            btnTest.Click += new EventHandler(btnTest_Click);
            this.Controls.Add(btnTest);
        }
        void btnTest_Click(object sender, EventArgs e)
        {
            //將自定義事件繫結到控制元件事件上
            if (myEvent != null)
            {
                myEvent(sender, e);
            }
        }
    }
}
 

2）窗體Form1.cs

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 WindowsFormsApplication28
{
    public partial class Form1 : Form
    {
        UserControl1 userControl1 = new UserControl1();
        TextBox textBox1 = new TextBox();
        public Form1()
        {
            InitializeComponent();
            //UserControl
            userControl1.Location = new Point(1, 1);
            //呼叫自定義事件
            userControl1.myEvent += new UserControl1.MyDelegate(userControl1_myEvent);
            this.Controls.Add(userControl1);
            //TextBox
            textBox1.Location = new Point(1, 1 + userControl1.Height + 1);
            this.Controls.Add(textBox1);
        }
        void userControl1_myEvent(object sender, EventArgs e)
        {
            textBox1.Text = "success";
        }
    }
}