try
        {
            if (!Directory.Exists(DirectoryTextBox.Text))
            {
                MsgLabel.Text = "该文件不存在";
                FileListBox.Visible = false;
                return;
            }
            else
            {
                DirectoryInfo dirinfo = new DirectoryInfo(DirectoryTextBox.Text);
                FileSystemInfo[] dirs = dirinfo.GetFileSystemInfos();
                if (dirs.Length < 1)
                {
                    MsgLabel.Text = "该文件夹为空！";
                    FileListBox.Visible = false;
                }
                else
                {
                    MsgLabel.Text = "该文件夹包含的文件和目录列表如下：";
                    FileListBox.Visible = true;
                    FileListBox.DataSource = dirs;
                    FileListBox.DataBind();
                }
            }
        }
        catch (Exception ee)
        {
            MsgLabel.Text = "操作失败！ 失败的原因是：" + ee.ToString();
        }