Android Studio实现多选题APP题目与对应选项同步随机化方案

当前APP的问题是随机题目时，仅单独打乱了question数组，导致题目索引和对应的choices、correctAnswer数组索引错位，无法同步显示对应选项和正确答案。以下是具体解决方法：

1. 重构数据结构，封装题目实体类 #

把题目、选项、正确答案封装成一个Question类，确保三者绑定，从根源上避免索引错位：

public class Question {
    private String questionText;
    private String[] choices;
    private String correctAnswer;

    public Question(String questionText, String[] choices, String correctAnswer) {
        this.questionText = questionText;
        this.choices = choices;
        this.correctAnswer = correctAnswer;
    }

    // Getter方法
    public String getQuestionText() {
        return questionText;
    }

    public String[] getChoices() {
        return choices;
    }

    public String getCorrectAnswer() {
        return correctAnswer;
    }
}

修改QuestionAnswer类，用List存储Question对象：

import java.util.ArrayList;
import java.util.List;

public class QuestionAnswer {
    public static List<Question> getQuestions() {
        List<Question> questions = new ArrayList<>();

        questions.add(new Question(
                "Who invented C++ ?",
                new String[]{"Dennis Retchie","Ken Thompson","Brian Kernighan","Bjarne Stroustrup"},
                "Bjarne Stroustrup"
        ));
        questions.add(new Question(
                "Which is not the programming language ?",
                new String[]{"Java","C++","Notepad++","Python"},
                "Notepad++"
        ));
        questions.add(new Question(
                "What is C++ ?",
                new String[]{"C++ is an object oriented programming language",
                        "C++ is a procedural programming language",
                        "C++ supports both procedural and object oriented programming language",
                        "C++ is a functional programming language"},
                "C++ supports both procedural and object oriented programming language"
        ));
        questions.add(new Question(
                "Which of the following is the correct syntax of including a user defined header files in C++ ?",
                new String[]{"#include [userdefined]","#include <userdefined.h>","#include “userdefined”","#include <userdefined>"},
                "#include “userdefined”"
        ));

        return questions;
    }
}

2. 修改Quiz类的逻辑适配新结构 #

调整变量和随机逻辑，确保题目与选项、答案同步：

import android.app.AlertDialog;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import java.util.Collections;
import java.util.List;

public class Quiz extends AppCompatActivity implements View.OnClickListener {

    TextView totalQuestion_tv, question_tv,score_tv;
    Button ansA, ansB, ansC, ansD, submitBtn,stopBtn;

    int score;
    List<Question> questionList;
    int totalQuestion;
    int currentQuestionIndex = 0;
    String selectedAnswer = "";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_quiz);
        getSupportActionBar().setDisplayHomeAsUpEnabled(false);

        totalQuestion_tv = findViewById(R.id.total_question);
        question_tv = findViewById(R.id.question);
        score_tv = findViewById(R.id.my_score);

        ansA = findViewById(R.id.ans_A);
        ansB = findViewById(R.id.ans_B);
        ansC = findViewById(R.id.ans_C);
        ansD = findViewById(R.id.ans_D);
        submitBtn = findViewById(R.id.submit_btn);
        stopBtn = findViewById(R.id.stop_btn);

        ansA.setOnClickListener(this);
        ansB.setOnClickListener(this);
        ansC.setOnClickListener(this);
        ansD.setOnClickListener(this);
        submitBtn.setOnClickListener(this);
        stopBtn.setOnClickListener(this);

        stopBtn.setBackgroundColor(Color.RED);

        // 初始化题目列表并随机打乱
        questionList = QuestionAnswer.getQuestions();
        totalQuestion = questionList.size();
        randomizeQuestions();

        totalQuestion_tv.setText("Total Question: "+totalQuestion);
        loadNewQuestion();
    }

    @Override
    public void onClick(View v) {
        ansA.setBackgroundColor(Color.WHITE);
        ansB.setBackgroundColor(Color.WHITE);
        ansC.setBackgroundColor(Color.WHITE);
        ansD.setBackgroundColor(Color.WHITE);

        Button click_btn = (Button) v;
        if(click_btn.getId()==R.id.submit_btn){
            if(selectedAnswer.equals(questionList.get(currentQuestionIndex).getCorrectAnswer())) {
                score++;
            }
            score_tv.setText("Score: "+score);
            currentQuestionIndex++;
            loadNewQuestion();
        }
        else if(click_btn.getId() == R.id.stop_btn){
            new AlertDialog.Builder(this)
                    .setTitle(" Quit Quiz ")
                    .setMessage("Are you sure you want to quit ?")
                    .setPositiveButton("Quit",((dialogInterface, x) -> finishQuiz()))
                    .setNegativeButton("Cancel",((dialogInterface, x) -> {}))
                    .setCancelable(false)
                    .show();
        }
        else{
            selectedAnswer = click_btn.getText().toString();
            click_btn.setBackgroundColor(Color.CYAN);
        }
    }

    private void loadNewQuestion() {
        if(currentQuestionIndex==totalQuestion){
            finishQuiz();
            return;
        }

        Question currentQuestion = questionList.get(currentQuestionIndex);
        question_tv.setText(currentQuestion.getQuestionText());
        String[] choices = currentQuestion.getChoices();
        ansA.setText(choices[0]);
        ansB.setText(choices[1]);
        ansC.setText(choices[2]);
        ansD.setText(choices[3]);
    }

    // 随机打乱整个题目列表，确保题目与选项、答案同步
    void randomizeQuestions(){
        Collections.shuffle(questionList);
    }

    void finishQuiz() {
        String passStatus = "";
        if(score > totalQuestion*0.60){
            passStatus = "Passed";
        }else{
            passStatus = "Failed";
        }

        int finalScore = score;
        score = 0;

        new AlertDialog.Builder(this)
                .setTitle(passStatus)
                .setMessage("Score is: "+finalScore+" out of "+ totalQuestion)
                .setPositiveButton("Restart",((dialogInterface, i) -> restartQuiz()))
                .setNegativeButton("Exit",((dialogInterface, i) -> finish()))
                .setCancelable(false)
                .show();
    }

    void restartQuiz() {
        score = 0;
        currentQuestionIndex = 0;
        randomizeQuestions();
        loadNewQuestion();
    }
}

关键修改说明 #

• 实体类封装：将题目、选项、正确答案绑定为一个对象，彻底避免索引错位问题
• 随机逻辑调整：不再单独打乱题目数组，而是打乱整个Question对象列表，确保每个题目对应的选项和答案始终同步
• 修复分数显示bug：原代码在弹窗显示前重置了分数，导致显示0分，现在先保存最终分数再重置
• 优化取消按钮逻辑：点击取消时直接关闭弹窗，无需重复加载题目

内容的提问来源于stack exchange，提问作者J i N A D A PH