Hashtable ht = new Hashtable();
        string s;
        public Form1()
        {
            InitializeComponent();
            s = Environment.CurrentDirectory + "//Image";         
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            DirectoryInfo dir = new DirectoryInfo(s);
            GetAllFiles(dir);
            foreach (DictionaryEntry de in ht)
                this.comboBox1.Items.Add(de.Key);
        }

        public void GetAllFiles(DirectoryInfo dir)
        {
            FileSystemInfo[] fileinfo = dir.GetFileSystemInfos();
            foreach (FileSystemInfo fsi in fileinfo)
            {
                if (fsi is DirectoryInfo)
                    GetAllFiles((DirectoryInfo)fsi);
                else
                {
                    string str = fsi.FullName;
                    int b = str.LastIndexOf("\\");
                    string strType = str.Substring(b + 1);
                    if (strType.Substring(strType.Length - 3) == ".jpg" || strType.Substring(strType.Length - 3) == "bmp")
                        ht.Add(strType.Substring(0, strType.Length - 4), strType);
                }
            }
        }

        public void showPic(string name)
        {
            this.pictureBox1.ImageLocation = s + "\\" + name;
        }

讀取圖片位置,用按鈕顯示出來