form1.cs

[huyandpeach]

// Form1.cs
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Windows.Forms;
using static System.Windows.Forms.VisualStyles.VisualStyleElement.Window;

namespace GeographyQuizGame
{
public partial class Form1 : Form
{
private List questions = new List();
private int currentIndex = 0;
private int correctCount = 0;
private Stopwatch timer = new Stopwatch();

    public Form1()
    {
        InitializeComponent();
        questionTypeComboBox.SelectedIndexChanged += QuestionTypeComboBox_SelectedIndexChanged;
        addButton.Click += AddButton_Click;
        editButton.Click += EditButton_Click;
        deleteButton.Click += DeleteButton_Click;
        questionListBox.SelectedIndexChanged += QuestionListBox_SelectedIndexChanged;
        submitAnswerButton.Click += SubmitAnswerButton_Click;
        showAnswersButton.Click += ShowAnswersButton_Click;
        restartButton.Click += RestartButton_Click;
        exitButton.Click += (s, e) => Close();

        questionTypeComboBox.SelectedIndex = 0;
        UpdateInputVisibility();
    }

    private void QuestionTypeComboBox_SelectedIndexChanged(object sender, EventArgs e)
    {
        UpdateInputVisibility();
    }

    private void UpdateInputVisibility()
    {
        multipleChoiceGroup.Visible = questionTypeComboBox.SelectedIndex == 0;
        trueFalseGroup.Visible = questionTypeComboBox.SelectedIndex == 1;
        openEndedGroup.Visible = questionTypeComboBox.SelectedIndex == 2;
    }

    private void AddButton_Click(object sender, EventArgs e)
    {
        Question q = CreateQuestionFromInputs();
        if (q != null)
        {
            questions.Add(q);
            RefreshQuestionList();
        }
    }

    private void EditButton_Click(object sender, EventArgs e)
    {
        if (questionListBox.SelectedIndex >= 0)
        {
            Question q = CreateQuestionFromInputs();
            if (q != null)
            {
                questions[questionListBox.SelectedIndex] = q;
                RefreshQuestionList();
            }
        }
    }

    private void DeleteButton_Click(object sender, EventArgs e)
    {
        if (questionListBox.SelectedIndex >= 0)
        {
            questions.RemoveAt(questionListBox.SelectedIndex);
            RefreshQuestionList();
        }
    }

    private void RefreshQuestionList()
    {
        questionListBox.Items.Clear();
        foreach (var q in questions)
            questionListBox.Items.Add(q.Text);
    }

    private void QuestionListBox_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (questionListBox.SelectedIndex >= 0)
        {
            LoadQuestionToForm(questions[questionListBox.SelectedIndex]);
        }
    }

    private void LoadQuestionToForm(Question q)
    {
        questionTextBox.Text = q.Text;

        if (q is MultipleChoiceQuestion mcq)
        {
            questionTypeComboBox.SelectedIndex = 0;
            mcOption1.Text = mcq.Options[0];
            mcOption2.Text = mcq.Options[1];
            mcOption3.Text = mcq.Options[2];
            mcOption4.Text = mcq.Options[3];
            mcCorrectOption.SelectedIndex = mcq.CorrectIndex;
        }
        else if (q is TrueFalseQuestion tfq)
        {
            questionTypeComboBox.SelectedIndex = 1;
            trueRadio.Checked = tfq.Answer;
            falseRadio.Checked = !tfq.Answer;
        }
        else if (q is OpenEndedQuestion oeq)
        {
            questionTypeComboBox.SelectedIndex = 2;
            acceptedAnswersTextBox.Text = string.Join(", ", oeq.AcceptedAnswers);
        }
    }

    private Question CreateQuestionFromInputs()
    {
        string text = questionTextBox.Text.Trim();
        if (string.IsNullOrEmpty(text)) return null;

        switch (questionTypeComboBox.SelectedIndex)
        {
            case 0:
                if (mcCorrectOption.SelectedIndex < 0) return null;
                return new MultipleChoiceQuestion(text,
                    new string[] { mcOption1.Text, mcOption2.Text, mcOption3.Text, mcOption4.Text },
                    mcCorrectOption.SelectedIndex);
            case 1:
                return new TrueFalseQuestion(text, trueRadio.Checked);
            case 2:
                var answers = acceptedAnswersTextBox.Text.Split(',').Select(a => a.Trim().ToLower()).ToList();
                return new OpenEndedQuestion(text, answers);
        }
        return null;
    }

    private void StartQuiz()
    {
        if (questions.Count == 0)
        {
            MessageBox.Show("No questions available.");
            return;
        }
        currentIndex = 0;
        correctCount = 0;
        resultLabel.Text = "";
        timer.Restart();
        LoadQuestion();
    }

    private void LoadQuestion()
    {
        if (currentIndex >= questions.Count)
        {
            timer.Stop();
            resultLabel.Text = $"Correct: {correctCount}/{questions.Count}\nTime: {timer.Elapsed.Minutes}m {timer.Elapsed.Seconds}s";
            return;
        }

        var q = questions[currentIndex];
        playQuestionLabel.Text = q.Text;
        playAnswerPanel.Controls.Clear();

        Control answerControl = q.GetAnswerControl();
        answerControl.Location = new System.Drawing.Point(0, 0);
        playAnswerPanel.Controls.Add(answerControl);
    }

    private void SubmitAnswerButton_Click(object sender, EventArgs e)
    {
        if (currentIndex < questions.Count)
        {
            var q = questions[currentIndex];
            bool correct = q.CheckAnswer(playAnswerPanel.Controls[0]);
            if (correct) correctCount++;
            currentIndex++;
            LoadQuestion();
        }
    }

    private void ShowAnswersButton_Click(object sender, EventArgs e)
    {
        string msg = string.Join("\n\n", questions.Select(q => $"{q.Text}\nAnswer: {q.GetCorrectAnswer()}"));
        MessageBox.Show(msg, "Correct Answers");
    }

    private void RestartButton_Click(object sender, EventArgs e)
    {
        StartQuiz();
    }

    private void falseRadio_CheckedChanged(object sender, EventArgs e)
    {

    }
}

public abstract class Question
{
    public string Text { get; set; }
    public Question(string text) => Text = text;
    public abstract Control GetAnswerControl();
    public abstract bool CheckAnswer(Control c);
    public abstract string GetCorrectAnswer();
}

public class MultipleChoiceQuestion : Question
{
    public string[] Options { get; set; }
    public int CorrectIndex { get; set; }
    public MultipleChoiceQuestion(string text, string[] options, int correctIndex) : base(text)
    {
        Options = options;
        CorrectIndex = correctIndex;
    }
    public override Control GetAnswerControl()
    {
        var panel = new Panel();
        for (int i = 0; i < Options.Length; i++)
        {
            var radio = new RadioButton { Text = Options[i], Location = new System.Drawing.Point(0, 25 * i), Tag = i };
            panel.Controls.Add(radio);
        }
        return panel;
    }
    public override bool CheckAnswer(Control c)
    {
        foreach (RadioButton rb in c.Controls)
        {
            if (rb.Checked && (int)rb.Tag == CorrectIndex)
                return true;
        }
        return false;
    }
    public override string GetCorrectAnswer() => Options[CorrectIndex];
}

public class TrueFalseQuestion : Question
{
    public bool Answer { get; set; }
    public TrueFalseQuestion(string text, bool answer) : base(text) => Answer = answer;
    public override Control GetAnswerControl()
    {
        var panel = new Panel();
        var trueRB = new RadioButton { Text = "True", Location = new System.Drawing.Point(0, 0), Tag = true };
        var falseRB = new RadioButton { Text = "False", Location = new System.Drawing.Point(0, 25), Tag = false };
        panel.Controls.Add(trueRB);
        panel.Controls.Add(falseRB);
        return panel;
    }
    public override bool CheckAnswer(Control c)
    {
        foreach (RadioButton rb in c.Controls)
        {
            if (rb.Checked && (bool)rb.Tag == Answer)
                return true;
        }
        return false;
    }
    public override string GetCorrectAnswer() => Answer ? "True" : "False";
}

public class OpenEndedQuestion : Question
{
    public List<string> AcceptedAnswers { get; set; }
    public OpenEndedQuestion(string text, List<string> answers) : base(text) => AcceptedAnswers = answers;
    public override Control GetAnswerControl()
    {
        return new TextBox { Width = 300 };
    }
    public override bool CheckAnswer(Control c)
    {
        string input = (c as TextBox).Text.Trim().ToLower();
        return AcceptedAnswers.Contains(input);
    }
    public override string GetCorrectAnswer() => string.Join(", ", AcceptedAnswers);
}

}