简单的工厂模式

 

private void btnCalc_Click(object sender, EventArgs e)
        {
            double total = 0.0d;
            string ctypeStr = icmbCtype.SelectedItem.ToString();
            css = DXSLFactory.CashFactory.CreateCashSuper(ctypeStr);
            double d = css.AcceptCash(double.Parse(txtMoney.Text)) * Convert.ToDouble(txtNumber.Text);
            total = total + d;
            listBoxControl1.Items.Add(string.Format("单价:{0}     数量:{1}      合计：{2} ", txtMoney.Text, txtNumber.Text, total));
        }

 public class CashFactory
    {
        /// <summary>
        /// 根据条件返回相应对象
        /// </summary>
        /// <param name="ctype"></param>
        /// <returns></returns>
        public static DXSLCashSuper.CashSuper CreateCashSuper(string ctype)
        {
            DXSLCashSuper.CashSuper css = null;
            switch (ctype)
            {
                case "正常收费":
                    CashNormal csn = new CashNormal();
                    css = csn;
                    break;
                case "满300返100":
                    CashRetrun csrt = new CashRetrun("300", "100");
                    css = csrt;
                    break;
                case "打8折":
                    CashRebate csrb = new CashRebate("0.8");
                    css = csrb;
                    break;
            }
            return css;
        }
    }

    /// <summary>
    /// 现金收取父类
    /// </summary>
    public abstract class CashSuper
    {
        /// <summary>
        /// 抽象方法，收取现金
        /// </summary>
        /// <param name="money">原价，返回为当前价格</param>
        /// <returns></returns>
        public abstract double AcceptCash(double money);
    }

    /// <summary>
    /// 正常收费，继承CashSuper
    /// </summary>
    public class CashNormal : CashSuper
    {
        public override double AcceptCash(double money)
        {
            return money;
        }
    }

    /// <summary>
    /// 打折收费，继承CashSuper
    /// </summary>
    public class CashRebate : CashSuper
    {
        private double moneyRebate = 1d;
        public CashRebate(string moneyRebate)
        {
            this.moneyRebate = double.Parse(moneyRebate);
        }
        public override double AcceptCash(double money)
        {
            return money * moneyRebate;
        }
    }

    /// <summary>
    /// 返利收费，继承CashSuper
    /// </summary>
    public class CashRetrun : CashSuper
    {
        private double moneyCondition = 0d;
        private double moneyReturn = 0d;

        public CashRetrun(string moneyCondition, string moneyReturn)
        {
            this.moneyCondition = double.Parse(moneyCondition);
            this.moneyReturn = double.Parse(moneyReturn);
        }
        public override double AcceptCash(double money)
        {
            double result = money;
            if (money >= moneyCondition)
                result = money - Math.Floor(money / moneyCondition) * moneyReturn;
            return result;
        }
    }