在 Taxpayer 类上实现 Icomparable 以根据 TaxOwed 进行排序

Question

我无法实现 Icomparable CompareTo 来根据所欠税款来比较 Taxpayer 对象..有人可以帮助我实现 Taxpayer 类的 icomparable 实现吗？ 我想像这里一样实现 icomparable - 接口对我来说是新主题..请帮助 http://www.dotnetperls。 com/icomparable

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

namespace Taxes
{
    class Rates
    {
        // Create a class named rates that has the following data members: 
        private int incomeLimit;
        private double lowTaxRate;
        private double highTaxRate;

        public int IncomeLimit  // use read-only accessor.
        { get { return incomeLimit; } }

        public double LowTaxRate // use read-only accessor.
        { get { return lowTaxRate; } }

        public double HighTaxRate // use read-only accessor.
        { get { return highTaxRate; } }

        //A class constructor that assigns default values of limit=30000, low rate = .15 and high rate = .28.
        public Rates()
        {
            int limit = 30000;
            double lowRate = .15;
            double highRate = .28;

            incomeLimit = limit;
            lowTaxRate = lowRate;
            highTaxRate = highRate;
        }

        //A class constructor that takes three parameters to assign input values for limit, low rate and high rate.
        public Rates(int limit, double lowRate, double highRate)
        {

        }

        //  A CalculateTax method that takes an income parameter and computes the tax as follows:
        public int CalculateTax(int income)
        {
            int limit = 0;
            double lowRate = 0;
            double highRate = 0;
            int taxOwed = 0;

            //  If income is less than the limit then return the tax as income times low rate.
            if (income < limit)
                taxOwed = Convert.ToInt32(income * lowRate);
            //  If income is greater than or equal to the limit then return the tax as income times high rate.
            if (income >= limit)
                taxOwed = Convert.ToInt32(income * highRate);
            return taxOwed;
        }
    }  //end class Rates

    //  Create a class named Taxpayer that has the following data members:
    public class Taxpayer
    {
        //Social Security number (use type string, no dashes between groups).  Use get and set accessors.
        string SSN
        { get; set; }

        int yearlyGrossIncome // Use get and set accessors.
        { get; set; }

        public int taxOwed  //  Use read-only accessor.
        {
            get { return taxOwed; }
        }

        // **  The Taxpayer class should be set up so that its objects are comparable to each other based on tax owed.
        class taxpayer : IComparable
        {
            public int taxOwed { get; set; }
            public int income { get; set; }

            int IComparable.CompareTo(Object o)
            {
                int returnVal;
                taxpayer temp = (taxpayer)o;
                if (this.taxOwed > temp.taxOwed)
                    returnVal = 1;
                else
                    if (this.taxOwed < temp.taxOwed)
                        returnVal = -1;
                    else
                        returnVal = 0;
                return returnVal;


            }  // End IComparable.CompareTo
        } //end taxpayer  IComparable class

        //  **The tax should be calculated whenever the income is set.
        //  The Taxpayer class should have a getRates class method that has the following.
        public static void GetRates()
        {
            //  Local method data members for income limit, low rate and high rate.
            int incomeLimit = 0;
            double lowRate;
            double highRate;
            string userInput;

            //  Prompt the user to enter a selection for either default settings or user input of settings.
            Console.Write("Would you like to enter your own values? (enter 0) or would you like to use the default values? (enter 1):  ");

            /*   If the user selects default the default values you will instantiate a rates object using the default constructor
            * and set the Taxpayer class data member for tax equal to the value returned from calling the rates object CalculateTax method.*/
            userInput = Convert.ToString(Console.ReadLine());

            if (userInput == "1")
            {
                Rates rates = new Rates();
                rates.CalculateTax(incomeLimit);
            } // end if

            /*  If the user selects to enter the rates data then prompt the user to enter values for income limit, low rate and high rate, 
             * instantiate a rates object using the three-argument constructor passing those three entries as the constructor arguments and 
             * set the Taxpayer class data member for tax equal to the valuereturned from calling the rates object CalculateTax method. */

            if (userInput == "0")
            {
                Console.Write("Please enter the income limit: ");
                incomeLimit = Convert.ToInt32(Console.ReadLine());
                Console.Write("Please enter the low rate: ");
                lowRate = Convert.ToDouble(Console.ReadLine());
                Console.Write("Please enter the high rate: ");
                highRate = Convert.ToDouble(Console.ReadLine());

                Rates rates = new Rates(incomeLimit, lowRate, highRate);
                rates.CalculateTax(incomeLimit);

            }  // end if
        }  //end GetRates class



        static void Main(string[] args)
        {
            //  instantiate an array of five (5) Taxpayer objects.

            string SSN = "0";
            int income = 0;
            int tax = 0;
            int x = 1;
            Taxpayer[] taxArray = new Taxpayer[5];


            //  Implement a for-loop that will prompt the user to enter the Social Security Number and gross income.
            for (x = 1; x < taxArray.Length; x++)
            {
                taxArray[x] = new Taxpayer();
                Console.Write("Please enter the Social Security Number for taxpayer {0}:  ", x);
                taxArray[x].SSN = Console.ReadLine();

                //SSN = String.Format("{0:000-00-0000}");
                Console.Write("Please enter the gross income for taxpayer {0}:  ", x);
                taxArray[x].yearlyGrossIncome = Convert.ToInt32(Console.ReadLine());

                Taxpayer.GetRates();

            }  //end for

            //  Implement a for-loop that will display each object as formatted taxpayer SSN, income and calculated tax.
            for (int i = 0; i < 5; i++)
            {

                Console.WriteLine("Taxpayer # {0} SSN: {1}, Income is {2:c}, Tax is {3:c}", i, SSN, income, tax);
            } // end for



            //  Implement a for-loop that will sort the five objects in order by the amount of tax owed and then display 
            //each object as formatted taxpayer SSN, income and calculated tax.

            Array.Sort(taxArray);
            Console.WriteLine("Sorted by tax owed");
            for (int i = 0; x < taxArray.Length; i++)
            {
                Console.WriteLine("Taxpayer # {0} SSN: {1}, Income is {2:c}, Tax is {3:c}", i, SSN, income, tax);


            }


        }  //end main
    } //  end Taxpayer class


}  //end namespace

//  Internal documentation

。

Answer 1

您需要在公共类上实现 IComparable 并消除私有 taxpayer 类。

这是 Taxpayer 类第一部分的重写：

public class Taxpayer : IComparable<Taxpayer>
{
    //Social Security number (use type string, no dashes between groups).  Use get and set accessors.
    string SSN
    { get; set; }

    int yearlyGrossIncome // Use get and set accessors.
    { get; set; }

    public int taxOwed  //  Use read-only accessor.
    {
        get { return taxOwed; }
    }

    #region IComparable<Taxpayer> Members

    int IComparable<Taxpayer>.CompareTo(Taxpayer other)
    {
        if (this.taxOwed > other.taxOwed)
            return 1;
        else
            if (this.taxOwed < other.taxOwed)
                return -1;
            else
                return 0;
    }

    #endregion

    //  **The tax should be calculated whenever the income is set.
    //  The Taxpayer class should have a getRates class method that has the following.
    public static void GetRates()

Answer 2

您已经实现了 IComparable 接口。我建议您使用 IComparable。

这是在 taxpayer 类上实现 IComparable 的方法：
您不需要在 CompareTo 方法内添加 if 语句。如果 this 的值较小且 other 的值较大，则返回负数。如果相反，则返回正值。如果相等则返回零。这就是将它们彼此相减的情况 this.taxOwed - other.taxOwed

class taxpayer : IComparable<taxpayer>
{
    public int taxOwed { get; set; }
    public int income { get; set; }

    public int CompareTo(taxpayer other)
    {
        return taxOwed - other.taxOwed;
    }
} //end taxpayer  IComparable 

如果您像这样使用它：

    public static List<taxpayer> taxPayers = new List<taxpayer>()
    {
        new taxpayer() { income = 1, taxOwed = 1000 },
        new taxpayer() { income = 2, taxOwed = 120 },
        new taxpayer() { income = 3, taxOwed = 7812 },
        new taxpayer() { income = 4, taxOwed = 4210 },
        new taxpayer() { income = 5, taxOwed = 400 },
        new taxpayer() { income = 6, taxOwed = 230 },
    };

    static void Main()
    {
        taxPayers.Sort();

        foreach (var t in taxPayers)
            Console.WriteLine(t.taxOwed);
    }

输出将是：

120
230
400
1000
4210
7812

Update 我对以下内容感到困惑代码，我没有注意到有两个类 taxpayer 和 Taxpayer。为什么你同时拥有它们？您只需要一个，就可以像上面一样实现 IComparable 。