不同颜色背景交替显示

for (int i = 0; i < DataList1.Items.Count; i++)
        {
            int row =i ; //i / 2 2为每行显示的列数
            if (row % 2 == 0)
            {
                DataList1.Items[i].CssClass = "testf";
            }
            else
            {
                DataList1.Items[i].CssClass = "tests";
            }
        }