問題描述

(C#) 我正在開發(fā)一個(gè)類似于 RedBox 的程序，它將具有客戶和經(jīng)理功能.我只是想在開始實(shí)現(xiàn)更多功能之前讓所有菜單正常工作，但我遇到了一個(gè)我似乎無法理解的錯(cuò)誤.我的問題似乎出在 CustomerMenu() 方法和 MainMenu() 方法中.我已經(jīng)添加了我擁有的所有內(nèi)容，以便您可以獲得完整的圖片.感謝任何幫助，因?yàn)槲胰匀挥悬c(diǎn)新，所以感謝任何提示，謝謝.

(C#) I am working on a program that is similar to RedBox which will have customer and manager functions. I am just trying to get all the menu's working correctly before I begin implementing more functions, but I am encountering an error that I can not seem to understand. My issue seems to be in the CustomerMenu() method and in the MainMenu() method. I have added all that I have so you can get the full picture. Any help is appreciated as I am still somewhat new so any tips are appreciated, thank you.

        MainMenu();
        Console.ReadKey();

    }
    static void MainMenu()
    {
        int userChoice = MainMenuChoice(); // Reading in the userChoice with the MenuChoice method

        if (userChoice == 3) // if user enters 3, the program ends
        {
            Console.WriteLine("Thank you, Goodbye!");
        }

        while (userChoice != 3)
        {
            if (userChoice == 1)
            {
                Console.WriteLine("Welcome to the customer menu!
"); // The customer menu is brought up if user enters 1
                CustomerMenu();
            }
            if (userChoice == 2)
            {
                Console.WriteLine("Welcome to the manager menu!
"); // The manager menu is brought up if user enters 2
                //ManagerMenu();
            }
            userChoice = MainMenuChoice(); // program ends
            if (userChoice == 3)
            {
                Console.WriteLine("Thank you for visiting VideoMart at University Boulevard, Goodbye!");

            }
        }

    }
    static int MainMenuChoice()
    {
        Console.WriteLine("-----------------------------------------------------------------------------------------------------------"); // introducing the user with the menu 
        Console.WriteLine("Welcome to VideoMart at University Boulevard!  
At VideoMart you are able to rent a variety of movies from many genres such as action, family, horror, etc!");
        Console.WriteLine("
Press 1 if you are a customer");
        Console.WriteLine("
Press 2 if you are a manager");
        Console.WriteLine("
Press 3 to Exit");
        Console.WriteLine("-----------------------------------------------------------------------------------------------------------");

        string choice = Console.ReadLine();
        Console.WriteLine();

        while (!(choice == "1" || choice == "2" || choice == "3")) // error checking
        {
            Console.WriteLine("Please try again");
            Console.WriteLine("Press 1 if you are a customer");
            Console.WriteLine("Press 2 if you are a manager");
            Console.WriteLine("Press 3 to Exit");

            choice = Console.ReadLine();
        }

        return int.Parse(choice);
    }

    }


    static void CustomerMenu() {

        int customerChoice = CustomerMenuChoice(); // Reading in the customerChoice into the CustomerMenuChoice method

        if (customerChoice == 5) // if user enters 5, the program ends
        {
            Console.WriteLine("Thank you for using VideoMart!");
        }

        while (customerChoice != 5)
        {
            if (customerChoice == 1)
            {
                Console.WriteLine("Press 1 to view movies available to rent.
"); // this option gives the user the opportunity to view all movies available to rent
                 //MoviesAvailable();
            }
            if (customerChoice == 2)
            {
                Console.WriteLine("Press 2 to rent a movie.
"); // this option gives the user the opportunity to rent a movie, with email address
                //RentMovie();
            }
            if (customerChoice == 3)
            {
                Console.WriteLine("Press 3 to view a list of movies you currently have rented.
"); // this option gives the user the opportunity to view movies a user currently has rented, with email address
                //RentMovie();
            }
            if (customerChoice == 4)
            {
                Console.WriteLine("Press 4 to return a movie rented.
"); // this option gives the user the opportunity to return a movie rented
                //RentMovie();
            }
            customerChoice = CustomerMenuChoice();
            if (customerChoice == 5)
            {
                Console.WriteLine("Thank you for visiting VideoMart at University Boulevard, Goodbye!");

            }
        }            
}
    static int CustomerMenuChoice()
    {
        Console.WriteLine("-----------------------------------------------------------------------------------------------------------"); // introducing the user with the menu 
        Console.WriteLine("Welcome to VideoMart at University Boulevard!  
Below is a list of actions that can be performed by customers!");
        Console.WriteLine("
Press 1 to view movies available to rent.");
        Console.WriteLine("
Press 2 to rent a movie.");
        Console.WriteLine("
Press 3 to view a list of movies you currently have rented.");
        Console.WriteLine("
Press 4 to return a movie rented.");
        Console.WriteLine("
Press 5 to exit.");
        Console.WriteLine("-----------------------------------------------------------------------------------------------------------");

        string customerChoice2 = Console.ReadLine();
        Console.WriteLine();

        while (!(customerChoice2 == "1" || customerChoice2 == "2" || customerChoice2 == "3" || customerChoice2 == "4") || customerChoice2 == "5") // error checking
        {
        Console.WriteLine("
Press 1 to view movies available to rent.");
        Console.WriteLine("
Press 2 to rent a movie.");
        Console.WriteLine("
Press 3 to view a list of movies you currently have rented.");
        Console.WriteLine("
Press 4 to return a movie rented.");
        Console.WriteLine("
Press 5 to exit.");

            customerChoice2 = Console.ReadLine();
        }

        return int.Parse(customerChoice2);
    }
}

推薦答案

使用平面菜單系統(tǒng)

您可以嘗試更正并稍微重構(gòu)一下.

You can try this corrected and a little refactored.

我們創(chuàng)建了一個(gè)獲取用戶選擇的方法，因此不再需要重復(fù)代碼.我們使用 uint 是因?yàn)檫x擇是肯定的，并且使用 TryParse 來轉(zhuǎn)換輸入的字符串.出錯(cuò)時(shí)返回 0，所以這里沒問題.

We created a method to get the user choice, so repeat code is no more needed. We use uint because choice is positive and TryParse to convert the inputed string. It returns 0 in case of error, so that's fine here.

我們還使用 lamda 來打印選擇字符串以不重復(fù)它們.

Also we use a lamda to print the choices strings to not repeat them.

接下來我們使用 switch 來管理選擇，以便代碼更干凈和可維護(hù).

Next we use a switch to manage choice so the code is more clean and maintainable.

清除菜單之間的控制臺(tái)，我們提供根菜單和子菜單之間的導(dǎo)航.

The console is cleared between menus and we offer navigation between root and sub menus.

未來的改進(jìn)是使用運(yùn)行這些表的自動(dòng)菜單管理器創(chuàng)建菜單標(biāo)題、選項(xiàng)和相關(guān)方法的表格.只是稍微復(fù)雜一點(diǎn)，但不要太多.這可以通過創(chuàng)建一些集合和一個(gè) MenuManager 類來完成.有了這樣的東西，你將擁有一個(gè)健壯的系統(tǒng)，代碼很少，沒有重復(fù).

A future improvement is to create tables of menus headers, choices and associated methods... with a auto-menu manager that runs these tables. Just a little more complex but not too much. It can be done by creating some collections and a MenuManager class. With such thing, you will have a robust system with very few code and nothing repeated.

static void Test()
{
  MainMenu();
}

static uint GetUserChoice(Action printMenu, int choiceMax)
{
  uint choice = 0;
  Action getInput = () =>
  {
    uint.TryParse(Console.ReadLine(), out choice);
  };
  getInput();
  while ( choice < 1 || choice > choiceMax )
  {
    Console.WriteLine();
    Console.WriteLine("Please try again");
    printMenu();
    getInput();
  }
  return choice;
}

static void MainMenu()
{
  Action printMenu = () =>
  {
    Console.WriteLine("Press 1 if you are a customer");
    Console.WriteLine("Press 2 if you are a manager");
    Console.WriteLine("Press 3 to Exit");
  };
  Console.Clear();
  Console.WriteLine("-----------------------------------------------------------------------------------------------------------"); // introducing the user with the menu 
  Console.WriteLine("Welcome to VideoMart at University Boulevard!");
  Console.WriteLine("At VideoMart you are able to rent a variety of movies from many genres such as action, family, horror, etc!");
  Console.WriteLine();
  printMenu();
  Console.WriteLine("-----------------------------------------------------------------------------------------------------------");
  uint choice = GetUserChoice(printMenu, 3);
  switch ( choice )
  {
    case 1:
      CustomerMenu();
      break;
    case 2:
      //ManagerMenu();
      break;
    case 3:
      Console.WriteLine("Thank you for visiting VideoMart at University Boulevard, Goodbye!");
      break;
    default:
      throw new NotImplementedException();
  }
}

static void CustomerMenu()
{
  Action printMenu = () =>
  {
    Console.WriteLine("Press 1 to view movies available to rent.");
    Console.WriteLine("Press 2 to rent a movie.");
    Console.WriteLine("Press 3 to view a list of movies you currently have rented.");
    Console.WriteLine("Press 4 to return a movie rented.");
    Console.WriteLine("Press 5 to return to main menu.");
  };
  Console.Clear();
  Console.WriteLine("-----------------------------------------------------------------------------------------------------------"); // introducing the user with the menu 
  Console.WriteLine("Below is a list of actions that can be performed by customers!");
  Console.WriteLine();
  printMenu();
  Console.WriteLine("-----------------------------------------------------------------------------------------------------------");
  Console.WriteLine();
  uint choice = GetUserChoice(printMenu, 5);
  switch ( choice )
  {
    case 1:
      //MoviesAvailable();
      break;
    case 2:
      //RentMovie();
      break;
    case 3:
      //RentedMovies();
      break;
    case 4:
      //ReturnMovie();
      break;
    case 5:
      MainMenu();
      break;
    default:
      throw new NotImplementedException();
  }
}

使用自動(dòng)菜單管理器

這是菜單選項(xiàng)類:

public class MenuChoice
{
  public string Title { get; private set; }
  public Action Action { get; private set; }
  public MenuChoice(string title, Action action)
  {
    Title = title;
    Action = action;
  }
}

這是菜單類:

public class Menu
{

  private readonly string Separator = new string('-', 100);
  private string Header;
  private List<MenuChoice> Choices;
  private Menu Root;

  public Menu(string header, List<MenuChoice> choices, Menu root)
  {
    Header = header;
    Choices = choices;
    Root = root;
  }

  private void Print()
  {
    for ( int index = 0; index < Choices.Count; index++ )
      Console.WriteLine($"Press {index + 1} {Choices[index].Title}");
      Console.WriteLine($"Press {Choices.Count + 1} to " + 
                        $"{( Root == null ? "exit" : "go to previous menu" )}");
  }

  public void Run()
  {
    Console.Clear();
    Console.WriteLine(Separator);
    Console.WriteLine(Header);
    Console.WriteLine();
    Print();
    Console.WriteLine(Separator);
    uint choice = GetUserChoice();
    if ( choice == Choices.Count + 1 )
      if ( Root == null )
      {
        Console.WriteLine("Thank you for visiting VideoMart at University Boulevard, Goodbye!");
        return;
      }
      else
        Root.Run();
    else
    {
      var action = Choices[(int)choice - 1].Action;
      if ( action != null )
        action();
      else
      {
        Console.WriteLine("Not implemented yet, press a key to continue.");
        Console.ReadKey();
        Run();
      }
    }
  }

  uint GetUserChoice()
  {
    uint choice = 0;
    Action getInput = () =>
    {
      uint.TryParse(Console.ReadLine(), out choice);
    };
    getInput();
    while ( choice < 1 || choice > Choices.Count + 1 )
    {
      Console.WriteLine();
      Console.WriteLine("Please try again");
      Print();
      getInput();
    }
    return choice;
  }

}

這是菜單管理器類:

public class MenuManager
{
  private Menu Root;

  public MenuManager(Menu root)
  {
    Root = root;
  }

  public void Run()
  {
    Root.Run();
  }
}

這里是菜單管理器的初始化，在選擇中使用方法或另一個(gè)菜單而不是空值:

Here the menu manager initialization, using methods or another menu instead of null in choices:

var choicesMain = new List<MenuChoice>();
var choicesCustomer = new List<MenuChoice>();
var choicesManager = new List<MenuChoice>();

string headerMain = "Welcome to VideoMart at University Boulevard!" + Environment.NewLine +
                    "At VideoMart you are able to rent a variety of movies from many genres such as action, family, horror, etc!";
string headerCustomer = "Below is a list of actions that can be performed by customers!";
string headerManager = "Below is a list of actions that can be performed by managers!";

var root = new Menu(headerMain, choicesMain, null);
var menuCustomer = new Menu(headerCustomer, choicesCustomer, root);
var menuManager = new Menu(headerManager, choicesManager, root);

choicesMain.Add(new MenuChoice("if you are a customer", menuCustomer.Run));
choicesMain.Add(new MenuChoice("if you are a manager", menuManager.Run));

choicesCustomer.Add(new MenuChoice("to view movies available to rent.", null));
choicesCustomer.Add(new MenuChoice("to rent a movie.", null));
choicesCustomer.Add(new MenuChoice("to view a list of movies you currently have rented.", null));
choicesCustomer.Add(new MenuChoice("to return a movie rented.", null));

現(xiàn)在要做的是:

new MenuManager(root).Run();

這篇關(guān)于如何在 C# 中實(shí)現(xiàn)具有子菜單的控制臺(tái)菜單的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！