private void btnOK_Click(object sender, EventArgs e)
        {
            //根据用户的选项,查询用户选择项的相关行
            DataRow dr = ((DataRow[])ds.Tables[0].Select("name='" + cbxType.SelectedItem.ToString() + "'"))[0];
            //声明一个参数的对象数组
            object[] args = null; //若有参数,则将其分割成字符串数组,用于实例化时所用的参数
            if (dr["para"].ToString() != "")
            {
                args = dr["para"].ToString().Split(',');
            }
            //通过反射实例化出相应的算法对象
            CashSuper cashSuper =
                (Assembly.Load("策略模式_计算器_满送_策略和工厂_反射")
                    .CreateInstance(
                        "策略模式_计算器_满送_策略和工厂_反射." + dr["class"].ToString(),
                        false,
                        BindingFlags.Default,
                        null,
                        args,
                        null,
                        null)) as CashSuper;
            CashContext cc = new CashContext(cashSuper);

            double totalPrices = 0d;
            totalPrices = cc.GetResult(Convert.ToDouble(txtPrice.Text) * Convert.ToDouble(txtNum.Text));
            total = total + totalPrices;
            lbxList.Items.Add(
                "单价:" + txtPrice.Text + " 数量:" + txtNum.Text + " " + cbxType.SelectedItem + " 合计:" + totalPrices.ToString());
            lblResult.Text = total.ToString();
        }
        private void btnOK_Click(object sender, EventArgs e)
        {
            //根据用户的选项,查询用户选择项的相关行
            DataRow dr = ((DataRow[])ds.Tables[0].Select("name='" + cbxType.SelectedItem.ToString() + "'"))[0];

            //声明一个参数的对象数组
            object[] args = null;             //若有参数,则将其分割成字符串数组,用于实例化时所用的参数
            if (dr["para"].ToString() != "")
            {
                args = dr["para"].ToString().Split(',');
            }
            //通过反射实例化出相应的算法对象
            CashSuper cashSuper =
                (Assembly.Load("策略模式_计算器_满送_策略和工厂_反射")
                 .CreateInstance(
                     "策略模式_计算器_满送_策略和工厂_反射." + dr["class"].ToString(),
                     false,
                     BindingFlags.Default,
                     null,
                     args,
                     null,
                     null)) as CashSuper;
            CashContext cc = new CashContext(cashSuper);

            double totalPrices = 0d;

            totalPrices = cc.GetResult(Convert.ToDouble(txtPrice.Text) * Convert.ToDouble(txtNum.Text));
            total       = total + totalPrices;
            lbxList.Items.Add(
                "单价:" + txtPrice.Text + " 数量:" + txtNum.Text + " " + cbxType.SelectedItem + " 合计:" + totalPrices.ToString());
            lblResult.Text = total.ToString();
        }