1。 还原

　　  private void menuOpen_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.InitialDirectory = ConfigurationManager.AppSettings["FilePath"] + "DataBase";
            ofd.Title = "请选择需要打开的数据文件";
            ofd.Filter = "xxx数据文件|*.xxx|所有文件|*.*"; //后面加上你需要打开的文件类型
            ofd.CheckFileExists = true;
            ofd.CheckPathExists = true;
            ofd.Multiselect = false;

            if (ofd.ShowDialog() == DialogResult.OK)
            {
                string basepath = GlobalParam.DataPath + @"DataBase\xxxxxx.xxx";
                string renamepath = basepath.Substring(0, basepath.Length - 4) +
                    DateTime.Now.ToString("yyyyMMddHHmmss") + ".xxx";

　　　　　　//重命名文件

                File.Move(basepath, renamepath);
                //拷贝文件

                File.Copy(ofd.FileName, basepath, true);                
            }
        }

　　 2。备份

        private void menuBackup_Click(object sender, EventArgs e)
        {
            SaveFileDialog sfd = new SaveFileDialog();
            sfd.Title = "保存";
            sfd.Filter = "xxx数据文件|*.xxx";
            sfd.CheckPathExists = true;
            sfd.RestoreDirectory = true;
            sfd.FileName = "xxxxxxx" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xxx";
            if (sfd.ShowDialog() == DialogResult.OK)
            {
                string basepath = GlobalParam.DataPath + @"DataBase\xxxxxxx.xxx";
                File.Copy(basepath, sfd.FileName, true);
            }
        }