c＃AutoScaleMode不能从UserControl继承

Question

i我需要用一个额外的Event扩展usercontrol类。 所以我决定创建自己的用户控件

 public partial class Custom_User_Control : Control
    {
        public Custom_User_Control()
        {
            InitializeComponent();
        }

        protected override void OnPaint(PaintEventArgs pe)
        {
            base.OnPaint(pe);
        }


        public event EventHandler<bool> finnished;

        #region protected members

        /// <summary>
        /// Calls the finnish event
        /// </summary>
        /// <param name="success">True if successfull</param>
        protected void On_Finnished(bool success)
        {
            finnished?.Invoke(this, success);
        }
        #endregion
    }

但是当我尝试创建新的custom_control实例

 public partial class My_First_Custom_User_control_Object: Custom_User_Control
{
}

设计师告诉我

this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;

未定义AutoscaleMode。为什么此属性不是从用户控件派生的？