C＃程序中的IComparable命名空间问题

Question

I'm working on a program that uses IComparable, and I'm following the code in the book, but it's not clear on where to put it exactly. I placed it in my Driver program, but in the original program, the main class is underlined, saying

"Error  1   The namespace 'Exercise6B' already contains a definition for 'TaxPayer2'

I tried changing things around and renaming my classes in each file, but then the TaxOwed field turns red. Any guidance would be helpful. I'm very new to C# and don't quite understand it.

Here's my code:

class TaxPayer2
{
    //Instance Fields
    private string ssn;
    private double grossIncome;
    private double taxOwed;

    private double incomeLimit;
    private double lowTaxRate;
    private double highTaxRate;

    public string Ssn
    {
        get { return ssn; }
        set { ssn = value; }
    }

    public double GrossIncome
    {
        get { return grossIncome; }
        set { grossIncome = value; }
    }

    public double TaxOwed
    {
        get
        {
            return taxOwed;
        }
    }

    public TaxPayer2()
    {
    }

    public TaxPayer2(string social, double income)
    {
        ssn = social;
        grossIncome = income;

        if (income < 30000)
        {
            taxOwed = .15 * income;
        }
        else
        {
            taxOwed = .28 * income;
        }

    }


    public TaxPayer2(double limit, double lowRate, double highRate)
    {
        incomeLimit = limit;
        lowTaxRate = lowRate;
        highTaxRate = highRate;
    }

} //end of TaxPayer main class

DRIVER

class TaxPayer2 : IComparable
{
        public string SSN { get; set; }
        public double Income { get; set; }
        //public double TaxOwed { get; }

    int IComparable.CompareTo(Object o)
    {
        int returnVal;
        TaxPayer2 temp = (TaxPayer2)o;
        if (this.taxOwed > temp.taxOwed)
            returnVal = 1;
        else if (this.taxOwed < temp.taxOwed)
                returnVal = -1;
        else returnVal = 0;
        return returnVal;
    }
}


class Driver
{
    static void Main()
    {

        TaxPayer2[] arrayTaxPayers = new TaxPayer2[10];

        for (int x = 0; x < 3; ++x)
        {
            Console.WriteLine("Enter SSN: ");
            string ssn = Console.ReadLine();

            Console.WriteLine("Enter Income: ");
            double income = Convert.ToDouble(Console.ReadLine());

            arrayTaxPayers[x] = new TaxPayer2(ssn, income);
        }

        for (int x = 0; x < 3; ++x)
        {
            Console.WriteLine("SSN {0} earned income of {1} and owes {2} in taxes.",
                arrayTaxPayers[x].Ssn, arrayTaxPayers[x].GrossIncome.ToString("C"), 
                arrayTaxPayers[x].TaxOwed.ToString("C"));

        }

        Array.Sort(arrayTaxPayers);
        Console.WriteLine("Sorted By Tax Owed:");
        for(int x=0; x<3; ++x)
        {
            Console.WriteLine("SSN {0} earned income of {1} and owes {2} in taxes.",
                arrayTaxPayers[x].Ssn, arrayTaxPayers[x].GrossIncome.ToString("C"),
                arrayTaxPayers[x].TaxOwed.ToString("C"));
        }

    }//end of Main
}//end of Driver

Answer 1

除非并且直到它们是局部类，否则在同一名称空间中不能有两个或多个相同类的定义（在您的情况下为TaxPayer2）。

Answer 2

Basic Skeleton should be something like this:

class TaxPayer2 : IComparable
{
  //properties 

  //methods

  //IComparable implementation
}

class Driver
{
    static void Main()
    {
      //the code you have in Main() here
    }
}

What the book prabably is showing is first the class declaration(without the IComparable implementation) and then they show you how to implement it in the same class,thats why you think the book is showing 2 different classes when there are only 1 and the same.To state the obvious you cant have 2 equal class declarations in the same namespace.