private void AddItem()
        {
            var arr = Enum.GetValues(typeof(StatisticTypes)) as StatisticTypes[];
            List <StaticItem> itemList = new List <StaticItem>();

            for (int i = 0; i < arr.Length; i++)
            {
                StaticItem item = new StaticItem();
                item.UC = GetUC(arr[i]);
                if (item.UC == null)
                {
                    continue;
                }
                item.Title = item.UC.Tag.ToString();
                itemList.Add(item);
            }
            flowLayout.ItemsSource = itemList;
        }
        private void GroupBox_StateChanged(object sender, DevExpress.Xpf.Core.ValueChangedEventArgs <GroupBoxState> e)
        {
            DevExpress.Xpf.LayoutControl.GroupBox group = sender as DevExpress.Xpf.LayoutControl.GroupBox;
            StaticItem       item = group.DataContext as StaticItem;
            IStatisticObject uc   = null;

            if (item != null && item.UC != null)
            {
                uc = item.UC as IStatisticObject;
            }
            if (group.State == GroupBoxState.Maximized)
            {
                uc.ShowLegend = true;
            }
            if (group.State == GroupBoxState.Normal)
            {
                uc.ShowLegend = false;
            }
        }