private void OnAddItem()
        {
            IItem item = this.itemFactory.CreateItem().Result;

            Dialogs.DialogItem.DialogItemViewModel vm = new Dialogs.DialogItem.DialogItemViewModel(item);
            DialogFactory dialogFactory = new DialogFactory();
            DialogResult  dialogResult  = dialogFactory.ShowDialog("Item", vm);
        }
        private void OnEditItem(object value)
        {
            if (value == null)
            {
                return;
            }

            Models.Models.Item item = value as Models.Models.Item;
            if (item == null)
            {
                return;
            }

            Dialogs.DialogItem.DialogItemViewModel vm = new Dialogs.DialogItem.DialogItemViewModel(item);
            DialogFactory dialogFactory = new DialogFactory();
            DialogResult  dialogResult  = dialogFactory.ShowDialog("Item", vm);
            //if (dialogResult == DialogResult.OK)
            //{
            //    OnPropertyChanged("Items");
            //}
        }
        private void OnDeleteItem(object value)
        {
            if (value == null)
            {
                return;
            }

            Models.Models.Item item = value as Models.Models.Item;
            if (item == null)
            {
                return;
            }

            string               message       = "Delete selected item?";
            DialogYesNoModel     m             = new DialogYesNoModel(message);
            DialogYesNoViewModel vm            = new DialogYesNoViewModel(m);
            DialogFactory        dialogFactory = new DialogFactory();
            DialogResult         dialogResult  = dialogFactory.ShowDialog("Delete", vm);

            if (dialogResult == DialogResult.YES)
            {
                this.model.DeleteItem(item.ID);
            }
        }