無法發送的數組，並在參考運行排序

Question

這個程序運行時，我得到以下輸出時的程序錯誤出來的時候從一個方法調用返回的值：

Please enter the Social Security Number for taxpayer 0: 111111111 
Please enter the gross income for taxpayer 0: 20000 
Please enter the Social Security Number for taxpayer 1: 555555555 
Please enter the gross income for taxpayer 1: 50000 
Please enter the Social Security Number for taxpayer 2: 333333333 
Please enter the gross income for taxpayer 2: 5464166 
Please enter the Social Security Number for taxpayer 3: 222222222 
Please enter the gross income for taxpayer 3: 645641 
Please enter the Social Security Number for taxpayer 4: 444444444 
Please enter the gross income for taxpayer 4: 29000 
Taxpayer # 1 SSN: 111111111, Income is $20,000.00, Tax is $0.00 
Taxpayer # 2 SSN: 555555555, Income is $50,000.00, Tax is $0.00 
Taxpayer # 3 SSN: 333333333, Income is $5,464,166.00, Tax is $0.00 
Taxpayer # 4 SSN: 222222222, Income is $645,641.00, Tax is $0.00 
Taxpayer # 5 SSN: 444444444, Income is $29,000.00, Tax is $0.00 

未處理的異常：System.InvalidOperationException：未能比較數組中的兩個元素。 ---> System.ArgumentException：至少有一個對象必須實現IComparable。
在System.Collections.Comparer.Compare（對象A，對象B）
在System.Collections.Generic.ObjectComparer`1.Compare（T X，T Y）
在System.Collections.Generic.ArraySortHelper`1 .SwapIfGreaterWithItems（T [] keys，IComparer`1 comparer，Int32 a，Int32 b）
at System.Collections.Generic.ArraySortHelper`1.QuickSort（T [] keys，Int32 left，Int32 right，IComparer`1 comparer）
在System.Collections.Generic.ArraySortHelper`1.Sort（T []按鍵，索引的Int32，的Int32長度，IComparer`1比較器）
---內部異常堆棧跟蹤的結尾---
在系統。 Collections.Generic.ArraySortHelper`1.Sort（T [] k在System.Array.Sort [T]（T []數組，Int32索引，Int32長度，IComparer`1比較器） 在System.Array.Sort [T ]（T []數組）
在Assignment5.Taxpayer.Main（字串[] args）在Program.cs中：線150

在通知應該是這樣的稅額的線的端部的0？ ??

下面是代碼：

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 incLimit; 
     private double lowTaxRate; 
     private double highTaxRate; 

     // use read-only accessor 
     public int IncomeLimit 
     { get { return incLimit; } } 
     public double LowTaxRate 
     { get { return lowTaxRate; } } 
     public double HighTaxRate 
     { get { return highTaxRate; } } 

     //A class constructor that assigns default values 
     public Rates() 
     { 
      int limit = 30000; 
      double lowRate = .15; 
      double highRate = .28; 
      incLimit = 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 
     { 
      //Use get and set accessors. 
      string SSN 
      { get; set; } 
      int grossIncome 
      { get; set; } 

      // Use read-only accessor. 
      public int taxOwed 
      { 
       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 incLimit = 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 the default values (D) or would you like to enter the values (E)?: "); 
        /* 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 == "D" || userInput == "d") 
        { 
         Rates rates = new Rates(); 
         rates.CalculateTax(incLimit); 
        } // 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 == "E" || userInput == "e") 
        { 
         Console.Write("Please enter the income limit: "); 
         incLimit = 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(incLimit, lowRate, highRate); 
         rates.CalculateTax(incLimit); 
        } 
       } 

      static void Main(string[] args) 
      { 

       Taxpayer[] taxArray = new Taxpayer[5]; 
       Rates taxRates = new Rates(); 
       // Implement a for-loop that will prompt the user to enter the Social Security Number and gross income. 
       for (int x = 0; x < taxArray.Length; ++x) 
       { 
        taxArray[x] = new Taxpayer(); 
        Console.Write("Please enter the Social Security Number for taxpayer {0}: ", x + 1); 
        taxArray[x].SSN = Console.ReadLine(); 

        Console.Write("Please enter the gross income for taxpayer {0}: ", x + 1); 
        taxArray[x].grossIncome = Convert.ToInt32(Console.ReadLine()); 

       } 

       Taxpayer.GetRates(); 

       // Implement a for-loop that will display each object as formatted taxpayer SSN, income and calculated tax. 
       for (int i = 0; i < taxArray.Length; ++i) 
       { 
        Console.WriteLine("Taxpayer # {0} SSN: {1}, Income is {2:c}, Tax is {3:c}", i + 1, taxArray[i].SSN, taxArray[i].grossIncome, taxRates.CalculateTax(taxArray[i].grossIncome)); 

       } // end for 
       // Implement a for-loop that will sort the five objects in order by the amount of tax owed 
       Array.Sort(taxArray); 
       Console.WriteLine("Sorted by tax owed"); 
       for (int i = 0; i < taxArray.Length; ++i) 
       { 
        Console.WriteLine("Taxpayer # {0} SSN: {1}, Income is {2:c}, Tax is {3:c}", i + 1, taxArray[i].SSN, taxArray[i].grossIncome, taxRates.CalculateTax(taxArray[i].grossIncome)); 

       } 
      } //end main 
     } // end Taxpayer class 

} //end 

任何線索，爲什麼金額就要到了爲0，爲什麼排序不工作？

Answer 1

• 你的第二個Rates構造函數什麼都不做。

• Taxpayer.taxOwed是無限遞歸的。

• 我不認爲有必要呼籲Convert.ToString一個字符串：

  userInput = Convert.ToString(Console.ReadLine()); 
  

• 你永遠不使用電話Rates.CalculateTax的結果。

• GetRates不會對它實例化的Rates對象做任何事情;稱它看起來什麼都不做。

• 嵌套類taxpayer似乎沒有用於任何東西。您是否試圖製作TaxpayerIComparable？您將在Taxpayer課中實施IComparable。你不應該定義一個單獨的類。您可能還想實施IComparable<Taxpayer>。

• 您正在使用您的程序類來處理您的數據。你應該把Taxpayer從你的程序類中分離出來。它應該是一個單獨的類，如Rates是。

Answer 2

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

你傳遞一個值給構造器，在沒有實現

//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) 
     { 
     } 

將值賦給這個構造內部的方法，並嘗試運行程序， 嘗試調試，並告訴我們在哪裏你面臨的問題。