将二维数组信息传递给 c# 中的方法

Posted 2023-04-13

【中文标题】将二维数组信息传递给 c# 中的方法

【英文标题】：Pass 2D Array Info to a method in c#

【发布时间】：2021-03-20 17:57:30

【问题描述】：

我有一个评估，我们必须在应用程序中实现方法以将员工信息存储在 2D 数组中并在屏幕上显示。到目前为止，代码可以像这样工作，但我无法找到将二维数组信息传递给开关的 case 2 的方法。当我尝试从 UserInput 方法返回数组信息或为案例 2 创建方法并尝试传递数组时，它总是会导致 IndexOutOfRangeException。这是我的代码，在此先感谢您的帮助：

using System;

namespace EmployeeFileWithMethods

  class Program
  
    static void Main(string[] args)
    
      int numberEmployees = 0;
      string[,] table = new string[numberEmployees, 4];
      string userInput = "1";
      while ( userInput != "0" )
      

        userInput = Intro();

        switch ( userInput )
        
          case "1":
            UserInput();
            break;
          case "2":
            Console.Clear();
            for ( int user = 0; user < table.GetLength(0); user++ )
            
              Console.WriteLine("     User " + ( user + 1 ));
              for ( int row = 0; row < table.GetLength(1); row++ )
              
                Console.Write(table[user, row] + "\n");
              
              Console.WriteLine("");
            
            break;
          case "0":
            break;
          default:
          
            DefaultCase();
            break;
          

        

      
      Console.WriteLine("Thanks for using the app!");
      Console.ReadLine();
    
    public static string Intro()
    
      Console.WriteLine("[-------------------------------------------------------------------------------]");
      Console.WriteLine("                        Welcome to the Edinburgh College App \n                             What would you like to do?\n                                   1:Add User\n                                   2:Show User Info\n                                   0:Exit");
      Console.WriteLine("[-------------------------------------------------------------------------------]");
      string userInput = Console.ReadLine();
      return userInput;
    
    public static void DefaultCase()
    
      Console.Clear();
      Console.WriteLine("[-------------------------------------------------------------------------------]");
      Console.WriteLine("              The option that you entered is invalid. Please try again.              ");
      Console.WriteLine("[-------------------------------------------------------------------------------]");
    
    public static void UserInput()
    
      Console.WriteLine("How many employees does your company have?");
      int numberEmployees = Convert.ToInt32(Console.ReadLine());
      string[,] table = new string[numberEmployees, 4];
      for ( int row = 0; row < numberEmployees; row++ )
      
        Console.WriteLine("Write the Forename of user " + ( row + 1 ));
        string forename = Console.ReadLine();
        table[row, 0] = forename;
        Console.WriteLine("Write the Surname of user " + ( row + 1 ));
        string surname = Console.ReadLine();
        table[row, 1] = surname;

        while ( true )
        
          Console.WriteLine("Write the Phone of user " + ( row + 1 ));
          string phone = Console.ReadLine();
          if ( phone.Length == 11 )
          
            table[row, 2] = phone;
            break;
          
          else
          
            Console.WriteLine("Invalid Phone Number. Please Try Again");
            continue;
          
        
        while ( true )
        
          Console.WriteLine("Write the Email of user " + ( row + 1 ));
          string email = Console.ReadLine();
          int charPos = email.IndexOf('@');
          if ( charPos > 0 )
          
            table[row, 3] = email;
            break;
          
          else
          
            Console.WriteLine("Invalid Email. Please Try Again");
            continue;
          
        

      
    
  

【参考方案1】：

我无法重现该异常，但UserInput 不返回任何内容，并且在此方法中初始化的表在返回时丢失。所以Main 中的表格的第一个暗淡的大小为 0。您应该通过 ref 将表格作为参数传递并删除方法中的表格声明：

UserInput(table);

public static void UserInput(ref string[,] table)

但是你需要调整这个数组的大小来添加新的输入。

更好、更简单、更健壮、更简洁的方法是使用类实体列表。这是经过调整和改进以使用员工实体列表的代码。我对代码进行了最低限度的修改，但可以对其进行更多改进和重构，尤其是 while 循环，您也可以使用 int.TryParse 来添加要添加的员工数量。

using System.Collections.Generic;

public class Employee

  public string Forename  get; set; 
  public string Surname  get; set; 
  public string Phone  get; set; 
  public string Email  get; set; 

static private void Main()

  var employees = new List<Employee>();
  string userInput = "1";
  while ( userInput != "0" )
  
    userInput = Intro();
    switch ( userInput )
    
      case "1":
        UserInput(employees);
        break;
      case "2":
        Console.Clear();
        for ( int index = 0; index < employees.Count; index++ )
        
          Console.WriteLine("     User " + ( index + 1 ));
          Console.WriteLine("         Forename: " + employees[index].Forename);
          Console.WriteLine("         Surname: " + employees[index].Surname);
          Console.WriteLine("         Phone: " + employees[index].Phone);
          Console.WriteLine("         eMail: " + employees[index].Email);
          Console.WriteLine("");
        
        break;
      case "0":
        break;
      default:
      
        DefaultCase();
        break;
      

    

  
  Console.WriteLine("Thanks for using the app!");
  Console.ReadLine();

public static void UserInput(List<Employee> employees)

  Console.WriteLine("How many employees does your company have?");
  int countEmployees = employees.Count;
  int countEmployeesNew = Convert.ToInt32(Console.ReadLine());
  for ( int indexEmployeeNew = 0; indexEmployeeNew < countEmployeesNew; indexEmployeeNew++ )
  
    int posEmployeeNew = countEmployees + indexEmployeeNew + 1;
    Console.WriteLine("Write the Forename of user " + posEmployeeNew);
    string forename = Console.ReadLine();
    Console.WriteLine("Write the Surname of user " + posEmployeeNew);
    string surname = Console.ReadLine();
    string phone = "";
    while ( true )
    
      Console.WriteLine("Write the Phone of user " + posEmployeeNew);
      phone = Console.ReadLine();
      if ( phone.Length == 11 ) break;
      Console.WriteLine("Invalid Phone Number. Please Try Again");
    
    string email = "";
    while ( true )
    
      Console.WriteLine("Write the Email of user " + posEmployeeNew);
      email = Console.ReadLine();
      int charPos = email.IndexOf('@');
      if ( charPos > 0 ) break;
      Console.WriteLine("Invalid Email. Please Try Again");
    
    employees.Add(new Employee
    
      Forename = forename,
      Surname = surname,
      Phone = phone,
      Email = email
    );