C＃将XML元素读取到2个单独的列表中

Question

我正在使用C＃作为控制台应用程序创建测验。

我有一个XML文件，其中包含a）问题b）答案和c）错误的答案。

我可以从XML文件中读取问题。

但是，我无法弄清楚我需要为每个随机生成的阅读问题关联错误和正确答案的逻辑。

这是我的XML文件的副本。

<?xml version="1.0" encoding="utf-8"?>
<Question xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <theQuestion>How many players in a football team?</theQuestion>
  <answerA>12</answerA>
  <answerB>10</answerB>
  <answerC>20</answerC>
  <answerD>11</answerD>
  <correctAnswer>11</correctAnswer>
  <theQuestion>How many minutes in a football game?</theQuestion>
  <answerA>90</answerA>
  <answerB>45</answerB>
  <answerC>60</answerC>
  <answerD>77</answerD>
  <correctAnswer>90</correctAnswer> 
</Question>

这是我的代码的一部分：

  ProcessData data = new ProcessData();

  //load questions from XML file and store in list
  var questions =  data.LoadQuizQuestions();

  //create a question object
  Question q = new Question();

  //get a question randomly generated from questions list 
  int index = new Random().Next(questions.Count);

  //display the randomly generated question
  Console.WriteLine(questions[index]);

  Console.ReadLine();

这是我的LoadQuizQuestions（）

    public List<string> LoadQuizQuestions()
    {
      //create empty list to store quiz questions read in from file
      List<string> questions = new List<string>();

      //load questions from file into list
      questions =
        XDocument.Load(@"C:\Development\Learning\Files\qsFile.xml").Descendants("theQuestion").Select(o => o.Value).ToList();

      //return list of questions
      return questions;
   }

我希望在显示每个随机问题时，也显示该问题的相关答案，并将“正确答案”读入一个变量，我可以根据该变量检查用户输入。

请帮助我了解我知道我将要钉牢这个:-)

谢谢

Answer 1

1. 将xml读入List<Question>集合
2. 选择一个随机物品
   1. 显示问题和选项
   2. 要求用户输入
   3. 比较用户输入和正确答案
3. 利润

编辑 ：您的XML输入将您的数据视为顺序的 ，而不是分层的； 当您尝试阅读问题时，这将导致潜在的问题。

您应该考虑这样的结构：

<Questions>
    <Question>
        <Title>How many players in a football team?</Title>
        <Options>
            <Option>12</Option>
            <Option>10</Option>
            <Option>20</Option>
            <Option IsCorrect='true'>11</Option>
        </Options>
    </Question>
    <Question>
        <Title>How many minutes in a football game?</Title>
        <Options>
            <Option IsCorrect='true'>90</Option>
            <Option>45</Option>
            <Option>60</Option>
            <Option>77</Option>
        </Options>
    </Question>
</Questions>

这将使手动读取XML或将其直接反序列化为List<Question>集合变得更加容易。

我做保留的选项，如果这是一个正确的答案，因为这可能是足够的灵活性，多个正确答案的决定。

class Question
{
    public string Title         { get; private set; }
    public List<Option> Options { get; private set; }

    public Question()
    {
    }

    public Question(XmlElement question) : this()
    {
        this.Title   = question["Title"].InnerText;
        this.Options = question.SelectNodes("Options/Option")
            .OfType<XmlElement>()
            .Select(option => new Option(option))
            .ToList();
    }
}

在这里没什么大不了的：我们只读取一个XmlElement并将项目反序列化委托给Option类。

class Option
{
    public string Title         { get; private set; }
    public bool   IsCorrect     { get; private set; }

    public Option()
    {
    }

    public Option(XmlElement option) : this()
    {
        this.Title = option.InnerText;
        this.IsCorrect = option.GetAttribute("IsCorrect") == "true";
    }
}

同样的交易。

通过这种结构，您可以执行以下操作：

var xml = new XmlDocument();
    xml.LoadXml(@"...");

var random = new Random();
var questions = xml.SelectNodes("//Question")
    .OfType<XmlElement>()
    .Select (question => new Question(question))
    .OrderBy(question => random.Next())
    .ToList();

foreach (var question in questions)
{
    Console.ForegroundColor = ConsoleColor.White;
    Console.WriteLine(question.Title);
    foreach (var option in question.Options)
    {
        Console.ForegroundColor = ConsoleColor.Gray;
        Console.WriteLine("\t{0}", option.Title);
    }
    Console.Write("Choose the right option: ");
    var answer = Console.ReadLine();

    if (question.Options.Any(option =>
        option.IsCorrect && answer.Equals(option.Title, 
            StringComparison.InvariantCultureIgnoreCase)))
    {
        Console.ForegroundColor = ConsoleColor.Green;
        Console.WriteLine("YOU HAVE CHOSEN... WISELY.");
    }
    else
    {
        Console.ForegroundColor = ConsoleColor.Red;
        Console.WriteLine("You have chosen poorly!");
    }
}

Answer 2

如果您使用包含答案列表的问题对象，如下所示：

public class Question
{
    public int ID { get; set; }
    public string QuestionText { get; set; }

    public List<Answer> Answers { get; set; } 

    public string AnswerText { get; set; }
}

public class Answer
{
    public string ID { get; set; }
    public string AnswerText { get; set; }
}

然后，您可以将问题和答案读入离散的对象中，例如下面的代码（免责声明：未对此进行测试，因此可能需要对其进行调整才能起作用）

   public List<Question> GetQuestions(string xmlFile)
    {
        var questions = new List<Question>();

        var xDoc = XDocument.Load(xmlFile);

        var questionNodes = xDoc.Descendants("theQuestion");

        foreach (var questionNode in questionNodes)
        {

            var question = new Question();
            question.QuestionText = questionNode.Value;

            // do something like this for all the answers
            var answer = new Answer();
            answer.ID = "A";
            var answerA = questionNode.Descendants("answerA").FirstOrDefault();
            if (answerA != null)
                answer.AnswerText = answerA.Value;

            question.Answers = new List<Answer>();
            question.Answers.Add(answer);

            question.AnswerText =
                questionNode.Descendants("correctAnswer").FirstOrDefault().Value;
        }

        return questions;
    } 
}

现在，您已经在单个对象中包含了问题和答案，可以显示问题，答案，然后根据用户输入进行字符串比较以检查用户的答案。

Answer 3

您可以检查我的逻辑以根据需要从XMLNode获取值。

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Answer 4

如果您可以更改xml结构，请执行以下操作：

<?xml version="1.0" encoding="utf-8"?>
<Questions>
  <Question text="How many players in a football team?">
    <answerA>12</answerA>
    <answerB>10</answerB>
    <answerC>20</answerC>
    <answerD>11</answerD>
    <correctAnswer>11</correctAnswer>
  </Question>
  <Question text="How many minutes in a football game?">
    <answerA>90</answerA>
    <answerB>45</answerB>
    <answerC>60</answerC>
    <answerD>77</answerD>
    <correctAnswer>90</correctAnswer>
  </Question>
</Questions>

然后使用以下类反序列化：

public class Questions
{
    [XmlElement("Question")]
    public List<Question> QuestionList { get; set; } = new List<Question>();
}

public class Question
{
    [XmlAttribute("text")]
    public string Text { get; set; }

    public string answerA { get; set; }
    public string answerB { get; set; }
    public string answerC { get; set; }
    public string answerD { get; set; }
    public string correctAnswer { get; set; }
}

这段代码：

string path = "yourxmlfile.xml";

XmlSerializer serializer = new XmlSerializer(typeof(Questions));

StreamReader reader = new StreamReader(path);
var qs = (Questions)serializer.Deserialize(reader);
reader.Close();