Dino`s Note

參考答案：

1.先實作ImplTax這個Class，目的是製作所得稅公式的框架和實作ITax這個interface

=================ImplTax=================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CSD04
{
    class ImplTax:ITax
    {
        int level;
        int minInc;
        int maxInc;
        double rate;
        int adjust;

        public ImplTax(int l,int min,int max,double r,int ad)
        {
            level = l;
            minInc = min;
            maxInc = max;
            rate = r;
            adjust = ad;
        }

        bool ITax.IsQualified(int Amount)
        {
            if (Amount >= minInc && Amount <= maxInc)
                return true;
            else
                return false;
        }

        int ITax.GetTax(int Amount)
        {
            return (int)Math.Round(Amount * rate - adjust);
        }

        int ITax.GetLevel()
        {
            return level;
        }
    }
}
 

=======================================

再來修改TaxCalculator，利用ImplTax製作的框架輸入所得稅計算的規則與數值

==================TaxCalculator============

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CSD04
{
    public class TaxCalculator
    {
        private static List<ITax> _taxStrategics = new List<ITax>();

        static TaxCalculator()
        {

            //TODO
            _taxStrategics.Add(new ImplTax(1, 0, 500000, 0.05, 0));
            _taxStrategics.Add(new ImplTax(2, 500001, 1130000, 0.12, 35000));
            _taxStrategics.Add(new ImplTax(3, 1130001, 2260000, 0.20, 124400));
            _taxStrategics.Add(new ImplTax(4, 2260001, 4230000, 0.30, 351400));
            _taxStrategics.Add(new ImplTax(5, 4230001, int.MaxValue, 0.40, 774400));

        }

        public static int GetTaxLevel(int Amount)
        {
            foreach (ITax taxStrategic in _taxStrategics)
            {
                if (taxStrategic.IsQualified(Amount))
                    return taxStrategic.GetLevel();
            }

            return 0;
        }

        public static int GetTaxAmount(int Amount)
        {
            foreach (ITax taxStrategic in _taxStrategics)
            {
                if (taxStrategic.IsQualified(Amount))
                    return taxStrategic.GetTax(Amount);
            }

            return 0;
        }
    }
}
 

=======================================

最後主程式做呼叫和顯示畫面(主要利用TaxCalculator提供的方法)

==================Program.cs==============

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CSD04
{
    class Program
    {
        static void Main(string[] args)
        {
            int amount1 = 827391;
            int amount2 = 334839;
            int amount3 = 1839203;
            int amount4 = 4827812;
            int amount5 = 3210292;

            // TODO: calculate the tax with given amount.
            Console.WriteLine("Amount: ${0:N0}, Lv: {1}, Tax: ${2:N0}", amount1, TaxCalculator.GetTaxLevel(amount1), TaxCalculator.GetTaxAmount(amount1));
            Console.WriteLine("Amount: ${0:N0}, Lv: {1}, Tax: ${2:N0}", amount2, TaxCalculator.GetTaxLevel(amount2), TaxCalculator.GetTaxAmount(amount2));
            Console.WriteLine("Amount: ${0:N0}, Lv: {1}, Tax: ${2:N0}", amount3, TaxCalculator.GetTaxLevel(amount3), TaxCalculator.GetTaxAmount(amount3));
            Console.WriteLine("Amount: ${0:N0}, Lv: {1}, Tax: ${2:N0}", amount4, TaxCalculator.GetTaxLevel(amount4), TaxCalculator.GetTaxAmount(amount4));
            Console.WriteLine("Amount: ${0:N0}, Lv: {1}, Tax: ${2:N0}", amount5, TaxCalculator.GetTaxLevel(amount5), TaxCalculator.GetTaxAmount(amount5));
            Console.ReadLine();
        }
    }
}
 

=======================================

執行結果：