策略模式与工厂结合(实现商场收银效果)

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

 

namespace 商场收银

{

    abstract class CashSuper

    {

        /// <summary>

        /// 现金收费抽象类

        /// </summary>

        /// <param name="money">原价</param>

        /// <returns>折扣价格</returns>

        public abstract double acceptCash(double money);

    }

 

    /// <summary>

    /// 二合一的具体效果实现1/2

    /// </summary>

    class CashContext

    {

        private CashSuper cs;

 

        /// <summary>

        ///构造函数，让传入具体的不同的子类实例化对象     

        /// </summary>

        /// <param name="type"></param>

        public CashContext(string type)

        {

            switch (type)

            {

                case "正常收费":

                    cs = new CashNormal();

                    break;

 

                case "满300返100":

                    cs = new CashReturn("300", "100");

                    break;

 

                case "打八折":

                    cs = new CashRebate("0.8");

                    break;

            }

        }

 

        public double GetResult(double money)

        {

            return cs.acceptCash(money);

        }

 

    }

 

    /// <summary>

    /// 简单工厂模式的具体实现效果1/2

    /// </summary>

    class CashFactory

    {

        public static CashSuper createCashAccept(string type)

        {

            CashSuper cs = null;

            switch (type)

            {

                case "正常收费":

                    cs = new CashNormal();

                    break;

 

                case "满300返100":

                    cs = new CashReturn("300", "100");

                    break;

 

                case "打8折":

                    cs = new CashRebate("0.8");

                    break;

            }

 

            return cs;

        }

    }

}

 

 

 

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

 

namespace 商场收银

{

    class CashNormal : CashSuper

    {

        /// <summary>

        /// 正常收费，原价返回。

        /// </summary>

        /// <param name="money"></param>

        /// <returns></returns>

        public override double acceptCash(double money)

        {

            return money;

        }

    }

 

    /// <summary>

    /// 打折收费类

    /// </summary>

    class CashRebate : CashSuper

    {

        //折扣率

        private double moneyRebate = 1d;

        public CashRebate(string moneyRebate)

        {

            this.moneyRebate = double.Parse(moneyRebate);

        }

 

        /// <summary>

        /// 打折收费

        /// </summary>

        /// <param name="money"></param>

        /// <returns></returns>

        public override double acceptCash(double money)

        {

            return money * moneyRebate;

        }

 

    }

 

    /// <summary>

    /// 返利收费

    /// </summary>

    class CashReturn : CashSuper

    {

        //例如，满300(moneyCondition),返回100(moneyReturn)。

        private double moneyCondition = 0.0d;

        private double moneyReturn = 0.0d;

 

        public CashReturn(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)

            {

                //这是看可以返回几次。

                result = money - Math.Floor(money / moneyCondition) * moneyReturn;

            }

            return result;

        }

    }

}

 

 

 

//main函数实现

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

 

namespace 商场收银

{

    public partial class FormMain : Form

    {

        public FormMain()

        {

            InitializeComponent();

        }

 

        //double类型来统计总数。

        double total = 0.0d;

 

        private void btnOk_Click(object sender, EventArgs e)

        {

            double totalPrices = 0d;

 

            ////简单工程的实现方式2/2

            //CashSuper csuper = CashFactory.createCashAccept(cbxType.SelectedItem.ToString());

            //totalPrices = csuper.acceptCash(Convert.ToDouble(txtPrice.Text) * Convert.ToDouble(txtNum.Text));

 

            ////策略模式的实现方式2/2

            //CashContext cc = null;

            //switch (cbxType.SelectedItem.ToString())

            //{

            //    case "正常收费":

            //        cc = new CashContext(new CashNormal());

            //        break;

 

            //    case "满300返100":

            //        cc = new CashContext(new CashReturn("300", "100"));

            //        break;

 

            //    case "打八折":

            //        cc = new CashContext(new CashRebate("0.8"));

            //        break;

            //}

            //totalPrices = cc.GetResult(Convert.ToDouble(txtPrice.Text) * Convert.ToDouble(txtNum.Text));

 

            //工厂策略二合一效果

            CashContext cc = new CashContext(cbxType.SelectedItem.ToString());

            totalPrices = cc.GetResult(Convert.ToDouble(txtPrice.Text) * Convert.ToDouble(txtNum.Text));

 

            total += totalPrices;

            lbxList.Items.Add("单价：" + txtPrice.Text + " 数量:" + txtNum.Text + " 总计：" + totalPrices);

            lbMess.Text = total.ToString();

        }

 

        private void button2_Click(object sender, EventArgs e)

        {

            total = 0;

            txtPrice.Text = "";

            txtNum.Text = "";

            lbMess.Text = null;

            lbxList.Items.Clear();

            cbxType.SelectedIndex = 0;

        }

 

        private void FormMain_Load(object sender, EventArgs e)

        {

            cbxType.Items.AddRange(new object[] { "正常收费", "满300返100", "打八折" });

            cbxType.SelectedIndex = 0;

        }

    }

}