protected override void OnPreRender(EventArgs e)
        {
            if (!DesignMode)
            {
                var users =
                    CutomerServiceExecutiveSetting.GetConfig().CutomerServiceExecutiveQuery.QueryCutomerServiceExecutive(Category.Split(','));

                if (users.Any())
                {
                    var title = new HtmlGenericControl("Span");
                    title.Attributes.Add("class", "csel_more");
                    title.InnerText = CutomerServiceExecutiveSetting.GetConfig().Title;
                    this.Controls.Add(title);



                    foreach (var u in users)
                    {
                        var userName = new HtmlGenericControl("Span");
                        userName.Attributes.Add("class", "csel_list");

                        UserPresence presence = new UserPresence();

                        presence.UserID          = u.ID;
                        presence.UserDisplayName = u.DisplayName;

                        userName.Controls.Add(presence);
                        this.Controls.Add(userName);

                        presence.EnsureInUserList();
                    }
                }
            }
            base.OnPreRender(e);
        }
        private void RenderCustomerService()
        {
            var users = CutomerServiceExecutiveSetting.GetConfig().CutomerServiceExecutiveQuery.QueryCutomerServiceExecutive(CustomerServiceCategory.Split(','));

            if (users.Any())
            {
                var divCustomerServiceControl = new HtmlGenericControl("div")
                {
                    ID = "divCustomerService"
                };
                divCustomerServiceControl.Attributes["class"] = "muiFirst mui-msg";
                divCustomerServiceControl.Controls.Add(new HtmlGenericControl("div")
                {
                    InnerText = "在线客服"
                });
                this.Controls.Add(divCustomerServiceControl);

                var divPanel = new HtmlGenericControl("div")
                {
                    ID = divCustomerServiceControl.ID + "_panel"
                };
                divPanel.Attributes["class"] = "mui";
                divPanel.Style[HtmlTextWriterStyle.Display] = "none";
                divCustomerServiceControl.Controls.Add(divPanel);

                var divTitle = new HtmlGenericControl("div")
                {
                    InnerText = "◆ 在线客服"
                };
                divTitle.Attributes["class"] = "mui-title";
                divPanel.Controls.Add(divTitle);

                var ul = new HtmlGenericControl("ul");
                ul.Attributes["class"] = "mui-content text-left ";
                divPanel.Controls.Add(ul);

                foreach (var u in users)
                {
                    var          li       = new HtmlGenericControl("li");
                    UserPresence presence = new UserPresence();

                    presence.UserID          = u.ID;
                    presence.UserDisplayName = u.DisplayName;

                    li.Controls.Add(presence);
                    ul.Controls.Add(li);

                    presence.EnsureInUserList();
                }
            }
        }
		public IEnumerable<IUser> QueryCutomerServiceExecutive(params string[] categories)
		{
			var result = new List<IUser>();

			if (categories.Any())
			{
				var executives = CutomerServiceExecutiveSetting.GetConfig()
					.CutomerServiceExecutives.Cast<CutomerServiceExecutiveElement>()
					.Where(q => categories.Contains(q.Category));

				if (executives.Any())
				{
					var logOnNames = executives.Select(r => r.LogOnName).ToArray();

					result =
						OguMechanismFactory.GetMechanism()
							.GetObjects<IUser>(SearchOUIDType.LogOnName, logOnNames)
							.Distinct((x, y) => string.Compare(x.ID, y.ID, true) == 0)
							.ToList();
				}
			}

			return result;
		}