c# 按键 图片 切换 写法

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 WindowsFormsApp2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string Path = Application.StartupPath.Substring(0, Application.StartupPath.Substring(0, Application.StartupPath.LastIndexOf("\\")).LastIndexOf("\\"));
            Path += @"\01.jpg";
            string Path2 = Application.StartupPath.Substring(0, Application.StartupPath.Substring(0, Application.StartupPath.LastIndexOf("\\")).LastIndexOf("\\"));
            Path2 += @"\02.jpg";
            Image Mimg = Image.FromFile(Path, true);
            imageList1.Images.Add(Mimg);
            Image Mimg2 = Image.FromFile(Path2, true);
            imageList1.Images.Add(Mimg2);
            imageList1.ImageSize = new Size(200, 165);
            pictureBox1.Width = 200;
            pictureBox1.Height = 165;
        }
        private void button1_Click(object sender, EventArgs e)
        {
            if (imageList1.Images.Count>0)
            {
                pictureBox1.Image = imageList1.Images[0];

            }
                
        }
        private void button2_Click(object sender, EventArgs e)
        {
            if (imageList1.Images.Count > 0)
            {
                pictureBox1.Image = imageList1.Images[1];
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (imageList1.Images.Count > 0)
            {
                //imageList1.Images.RemoveAt(0);
                pictureBox1.Image = null;
            }
            else {
                MessageBox.Show("图片不存在");
            }

        }
    }
}