protected void lbtnModify_Click(object sender, EventArgs e)
    {
        switch (lbtnModify.Text)
        {
        case "更新":
            if (lbItemID.Text == "" || txtItemName.Text == "" || txtArea.Text == "")
            {
                panelAttention.Visible = true;
                lbAttention.Text       = "请先选择更新的商品并填写相关信息!";
            }
            else
            {
                Entity.Items item = new Entity.Items();
                item.setItemID(int.Parse(lbItemID.Text));
                item.setProductID(int.Parse(ddlProductID.SelectedItem.Value));
                item.setBrandID(int.Parse(ddlBrandID.SelectedItem.Value));
                item.setName(txtItemName.Text.Trim());
                item.setArea(txtArea.Text.Trim());
                if (items.UpdateSingleItem(item))
                {
                    panelSuccess.Visible   = true;
                    lbSuccess.Text         = "商品信息更新成功!";
                    gvItemsList.DataSource = items.GetItemByAllWithNoImg();
                    gvItemsList.DataBind();
                    txtArea.Text = txtItemName.Text = lbItemID.Text = "";
                }
                else
                {
                    panelError.Visible = false;
                    lbError.Text       = "商品信息更新失败!";
                }
            }
            break;

        case "删除":
            if (lbItemID.Text == "")
            {
                panelAttention.Visible = true;
                lbAttention.Text       = "请先选择更新的商品并填写相关信息!";
            }
            else
            {
                if (items.DeleteItem(int.Parse(lbItemID.Text)))
                {
                    panelSuccess.Visible   = true;
                    lbSuccess.Text         = "商品信息删除成功!";
                    gvItemsList.DataSource = items.GetItemByAllWithNoImg();
                    gvItemsList.DataBind();
                }
                else
                {
                    panelError.Visible = true;
                    lbError.Text       = "商品信息删除失败!";
                }
            }
            break;
        }
    }