C＃winform 窗体事件和委托结合用法

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

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {

        private TextBox box; //文本框

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            //label1.Text = "我是按钮按下事件";
        }

        private void button2_Click(object sender, EventArgs e)
        {
           
        }

        private void button1_MouseDown(object sender, MouseEventArgs e)
        {
            label1.Text = "我是按钮按下事件";
        }

        private void button2_MouseUp(object sender, MouseEventArgs e)
        {
            label2.Text = "我是按钮松开事件";
        }

        private void 单击事件(object sender, EventArgs e)
        {
            label1.Text = "";
            label2.Text = "";
        }
    }
}

效果