试图找出如何以不同的方法访问列表

Question

这是我班上的代码。我正试图找出如何访问DisplayQuestion中的问题列表。我有一个program.cs，显示一个测验菜单，我不能有任何静态。

public string Question { get; set; }
public List<string> Choices { get; set; }
public char[] CorrectChoice = { 'A', 'B', 'C', 'D' };
public List<string> Questions { get; set; }

这是我课堂上的方法。我需要在这个课程中多次访问这个列表。

public void NewQuestion()
{
        Questions = new List<string>();
        Choices = new List<string>();
        Console.WriteLine("Enter the question: ");
        Questions.Add(Console.ReadLine());
        Console.WriteLine("Enter Choice 1 for the question:");
        Choices.Add(Console.ReadLine());
        Console.WriteLine("Enter Choice 2 for the question: ");
        Choices.Add(Console.ReadLine());
        Console.WriteLine("Enter Choice 3 for the question: ");
        Choices.Add(Console.ReadLine());
        Console.WriteLine("Enter Choice 4 for the question:");
        Choices.Add(Console.ReadLine());
       // Console.WriteLine("Enter the correct choice(A,B,C,D)");


        foreach (string choice in Choices)
        {
            Console.WriteLine();
            Console.WriteLine(choice);
        }
    } 

    public void DisplayQuestions()
    {
       foreach(string question in Questions)
        {
            Console.WriteLine();
            Console.WriteLine(question);
        }  
    }

Answer 1

尝试在全局部分中声明并初始化为null，或者为其创建一个具有适当getter setter方法的类。

Answer 2

不要觉得只能在一堂课中做所有事情。即使是将问题分离到单独的类中的粗略，冗长的尝试也有助于可读性，可维护性和理智性。然后，你只是一个远离优秀代码的深思熟虑的重构。

您正在使用面向OBJECT语言的C＃。因此，请使用对象进行处理。

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

namespace Quiz_StackOverflow
{
    class Program
    {
        static void Main(string[] args)
        {
            var quizGenerator = new QuizGenerator();
            var quiz = quizGenerator.GenerateQuiz();
            var quizProctor = new QuizProctor();
            var grade = quizProctor.ProctorQuiz(quiz);
            Console.WriteLine(grade.ToString());
            Console.WriteLine("Done. Press any key to exit.");
            Console.ReadKey();
        }
    }

    public class QuizGenerator
    {
        public Quiz GenerateQuiz()
        {
            var problems = GenerateProblems();
            var quiz = new Quiz()
            {
                Problems = problems
            };
            return quiz;
        }

        private List<Problem> GenerateProblems()
        {
            List<Problem> problems = new List<Problem>();
            int numChoices = InputValidator.GetPositiveNumber("Enter number of problems:  ");
            for (int i = 0; i < numChoices; i++)
            {
                Problem problem = GenerateProblem();
                problems.Add(problem);
            }
            return problems;
        }

        private Problem GenerateProblem()
        {
            var question = GenerateQuestion();
            var choices = GenerateChoices();
            var answer = GenerateAnswer(choices);
            var problem = new Problem()
            {
                Question = question,
                Choices = choices,
                Answer = answer
            };
            return problem;
        }

        private string GenerateQuestion()
        {
            Console.WriteLine("Enter the question: ");
            string question = Console.ReadLine();
            return question;
        }

        private List<string> GenerateChoices()
        {
            List<string> choices = new List<string>();
            int numChoices = InputValidator.GetPositiveNumber("Enter number of choices for the question:  ");
            for (int i=1; i<=numChoices; i++)
            {
                string choice = GenerateChoice(i);
                choices.Add(choice);
            }
            return choices;
        }

        private string GenerateChoice(int index)
        {
            Console.WriteLine($"Enter Choice {index} for the question: ");
            string choice = Console.ReadLine();
            return choice;
        }

        private Answer GenerateAnswer(List<string> choices)
        {
            Console.WriteLine("Enter the answer: ");
            string userChoice = InputValidator.GetUserChoice(new Problem() { Choices=choices });
            var answer = new Answer()
            {
                Value = userChoice
            };
            return answer;
        }
    }

    public class QuizProctor
    {
        public Grade ProctorQuiz(Quiz quiz)
        {
            var answers = new List<Answer>();
            foreach(Problem problem in quiz.Problems)
            {
                Answer answer = ProctorProblem(problem);
                answers.Add(answer);
            }
            Grade grade = quiz.Grade(answers);
            return grade;
        }

        private Answer ProctorProblem(Problem problem)
        {
            string userChoice = InputValidator.GetUserChoice(problem);
            var answer = new Answer()
            {
                Value = userChoice
            };
            return answer;
        }
    }

    public class Quiz
    {
        public List<Problem> Problems { get; set; }

        public Grade Grade(List<Answer> answers)
        {
            List<Answer> answerKey = Problems.Select(x => x.Answer).ToList();
            var rawResults = new List<Tuple<Answer, Answer>>();
            for(int i=0; i<answers.Count; i++)
            {
                Answer correct = answerKey[i];
                Answer provided = answers[i];
                rawResults.Add(new Tuple<Answer, Answer>(correct, provided));
            }
            return new Grade(rawResults);
        }
    }

    public class Grade
    {
        private List<Tuple<Answer, Answer>> RawResults { get; set; }
        public decimal Percent
        {
            get { return decimal.Divide(RawResults.Count(x => x.Item1.Equals(x.Item2)), RawResults.Count); }
        }

        public Grade(List<Tuple<Answer, Answer>> rawResults)
        {
            RawResults = rawResults;
        }

        public override string ToString()
        {
            return string.Format("You scored a {0:P2}.", Percent);
        }
    }

    public class Problem
    {
        public string Question { get; set; }
        public List<string> Choices { get; set; }
        public Answer Answer { get; set; }

        public string Prompt()
        {
            Func<int, char> numberToLetter = (int n) =>
            {
                return (char)('A' - 1 + n);
            };

            string prompt = Question;
            for (int i=0; i<Choices.Count; i++)
            {
                string choice = Choices[i];
                prompt += $"\n{numberToLetter(i+1)}) {choice}";
            }
            return prompt;
        }
    }

    public class Answer
    {
        public string Value { get; set; }

        public override string ToString()
        {
            return Value + "";
        }

        public override bool Equals(object obj)
        {
            if (obj == null || GetType() != obj.GetType())
            {
                return false;
            }
            return (obj as Answer).Value.Equals(Value);
        }

        public override int GetHashCode()
        {
            return Value.GetHashCode();
        }
    }

    public static class InputValidator
    {
        public static int GetPositiveNumber(string prompt)
        {
            int number = -1;
            while (number < 0)
            {
                Console.Write(prompt);
                string input = Console.ReadLine();
                try
                {
                    number = int.Parse(input);
                }
                catch (Exception)
                {
                    Console.WriteLine("ERROR: Please input a positive number.");
                }
            }
            return number;
        }

        public static string GetUserChoice(Problem problem)
        {
            Func<char, int> letterToNumber = (char c) =>
            {
                if (char.IsLower(c))
                {
                    return (int)(c - 'a' + 1);
                }
                return (int)(c - 'A' + 1);
            };

            char userChoiceLetter = '_';
            while (!char.IsLetter(userChoiceLetter))
            {
                Console.WriteLine(problem.Prompt());
                Console.Write("Answer:  ");
                var input = Console.ReadLine();
                try
                {
                    userChoiceLetter = char.Parse(input);
                }
                catch (Exception)
                {
                    Console.WriteLine("ERROR: Please input a letter corresponding to your choice.");
                }
            }
            int answerIndex = letterToNumber(userChoiceLetter) - 1;
            return problem.Choices[answerIndex];
        }
    }
}