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;using System.IO;namespace ImageCheck{ public partial class Form1 : Form {  public Form1()  {   InitializeComponent();  }  int index;  private void button1_Click(object sender, EventArgs e)  {   index--;   if (index<0)   {    MessageBox.Show("去往最后一張圖片");    index = imageList1.Images.Count - 1;   }   this.pictureBox1.Image = this.imageList1.Images[index];  }  private void button2_Click(object sender, EventArgs e)  {   index++;   if (index>imageList1.Images.Count-1)   {    MessageBox.Show("回到第一張圖片");    index = 0;   }   this.pictureBox1.Image = this.imageList1.Images[index];  }  private void LoadImage()  {   string rootPath = Application.StartupPath;   string filePath = rootPath + @"/image";   DirectoryInfo rootDir = new DirectoryInfo(filePath);   FileInfo[] file = rootDir.GetFiles();   for (int i=0;i<=file.Length-1;i++)   {    Image img = Image.FromFile(file[i].FullName);    this.imageList1.Images.Add(img);   }  }  private void Form1_Load(object sender, EventArgs e)  {   LoadImage();   this.pictureBox1.Image = this.imageList1.Images[index];  } }}