/// <summary>
        /// 设置按钮的启用状态。
        /// </summary>
        /// <param name="controls">指定的控件的集合。</param>
        /// <param name="enabled">指定的状态。</param>
        private void SetButtonEnabledState(Control.ControlCollection controls, bool enabled)
        {
            foreach (Control c in controls)
            {
                if (c is Button)
                {
                    c.Enabled = enabled;
                }
                else
                {
                    if (c.Controls.Count > 0)
                    {
                        EnabledButton(c.Controls, enabled);
                    }
                }
            }
        }