程式碼如下：

 寫屬性時注意是 public StateL _LoginState

        private StateL LoginState = StateL.Online;
        /// <summary>
        /// 登入狀態
        /// </summary>
        public StateL _LoginState
        {
            get
            {
                return LoginState;
            }
            set
            {
                this.LoginState = value;
                this.Invalidate();
            }
        }

        public enum StateL
        {
            [Description("線上")]
            Online = 1,
            [Description("Q我吧")]
            QMe = 2,
            [Description("離開")]
            Away = 3,
            [Description("忙碌")]
            Busy = 4,
            [Description("請勿打擾")]
            DontDisturb = 5,
            [Description("隱身")]
            Invisible = 6,
            [Description("離線")]
            Offline = 7
        }