android - 检查 Recyclerview Adapter 中的单选按钮状态并从 MainActivity 对其应用更改

Question

在我的 MainActivity 方法中，checkAnswer 和 showSolution 必须修改，因为我将 RecycleView 适配器添加到项目并将所有 View 项移动到 QuestionAdapter。我不明白我应该如何在 QuestionAdapter 中使用 isChecked 检查 rbGroup 单选按钮的状态并将其 id 传递给 MainActivity。我试着检查一下:Radiogroup in recyclerview但我仍然不清楚下一步应该采取什么步骤。有人可以给我基本的指导，从现在开始修改我的项目应该采取什么步骤。仍然找不到在回收 View 中处理单选按钮列表的答案或教程。如何使用 MainActivity 的界面检查单选按钮状态？

按照建议进行了一些更新。不明白我应该如何修改 showSolution 方法。

public class MainActivity extends AppCompatActivity {

public QuestionAdapter adapter;
public ArrayList<Question> questionList;
private int questionCountTotal;
private long backPressedTime;
private int score;
private int questionCounter;
private Button btnConfirmNext;
private boolean answered;
private Question currentQuestion;
private TextView tvQuestion, tvScore, tvQuestionCount, tvCountdown;
public QuizDbHelper dbHelper;
RecyclerView recyclerView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btnConfirmNext = findViewById(R.id.confirm_button);
    tvCountdown = findViewById(R.id.count_down);
    tvScore = findViewById(R.id.text_view_score);

    recyclerView = findViewById(R.id.recycler_view);
    recyclerView.setNestedScrollingEnabled(false);
    recyclerView.addItemDecoration(new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL));
    questionList = new ArrayList<>();
    adapter = new QuestionAdapter(this, questionList);

    RecyclerView.LayoutManager mLayoutManager = new GridLayoutManager(this, 1);
    recyclerView.setLayoutManager(mLayoutManager);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setAdapter(adapter);

    dbHelper = new QuizDbHelper(this);
    questionList = dbHelper.getAllQuestions();
    questionCountTotal = questionList.size();
    Collections.shuffle(questionList);

        prepareQuestion();

    btnConfirmNext.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            checkAnswer();
        }
    });

}


private void prepareQuestion() {
    adapter = new QuestionAdapter(getApplicationContext(), questionList);
    recyclerView.setAdapter(adapter);
    if (questionCounter < questionCountTotal) {
        currentQuestion = questionList.get(questionCounter);

        answered = false;
        btnConfirmNext.setText("Confirm");

    } else {
        finishQuiz();
    }
}


//How should I handle it in onbindViewHolder

private void checkAnswer() {
    answered = true;
    countDownTimer.cancel();
    RadioButton rbSelected = findViewById(rbGroup.getCheckedRadioButtonId());
    int answerNb = rbGroup.indexOfChild(rbSelected) + 1;

    if (answerNb == currentQuestion.getAnswerNB()) {
        score++;
        tvScore.setText("Score: " + score);
    }
    showSolution();
}

//How should I change state of the items in recycle view

private void showSolution() {
    rb1.setTextColor(Color.RED);
    rb2.setTextColor(Color.RED);
    rb3.setTextColor(Color.RED);
    rb4.setTextColor(Color.RED);

    switch (currentQuestion.getAnswerNB()) {
        case 1:
            rb1.setTextColor(Color.GREEN);
            break;
        case 2:
            rb2.setTextColor(Color.GREEN);
            break;
        case 3:
            rb3.setTextColor(Color.GREEN);
            break;
        case 4:
            rb4.setTextColor(Color.GREEN);
            break;
    }

    btnConfirmNext.setText("Finish");

}

问题适配器

public class QuestionAdapter extends RecyclerView.Adapter<QuestionAdapter.MyViewHolder> {

public ArrayList<Question> questionList;

public class MyViewHolder extends RecyclerView.ViewHolder {
    public TextView tvQuestion, tvScore, tvQuestionCount, tvCountdown;
    public RadioGroup rbGroup;
    public RadioButton rb1, rb2, rb3, rb4;



    public MyViewHolder(View view) {
        super(view);
        tvQuestion = view.findViewById(R.id.question);
        rbGroup = view.findViewById(R.id.radiog_group);
        rb1 = view.findViewById(R.id.radio_button1);
        rb2 = view.findViewById(R.id.radio_button2);
        rb3 = view.findViewById(R.id.radio_button3);
        rb4 = view.findViewById(R.id.radio_button4);
    }
}


public QuestionAdapter(Context mContext, ArrayList<Question> questionList) {
    this.questionList = questionList;
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.question_card, parent, false);


    return new MyViewHolder(itemView);
}

@NonNull
@Override
public void onBindViewHolder(final MyViewHolder holder, int position) {
    final Question question = questionList.get(position);
    holder.tvQuestion.setText(question.getQuestion());
    holder.rb1.setText(question.getOption1());
    holder.rb2.setText(question.getOption2());
    holder.rb3.setText(question.getOption3());
    holder.rb4.setText(question.getOption4());

    holder.rbGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup radioGroup, @IdRes int i) {

// How can I handle Check status here and pass it to main activity?

        }
    });
}

@Override
public int getItemCount() {
    return questionList.size();
}
}

更新。 在向我的 QuestionAdapter 添加接口(interface)并对构造函数和其他部分进行更改后，我在 MainActivity 中的 checkAnswer 看起来像这样

    private void checkAnswer() {
    answered = true;
    countDownTimer.cancel();
    adapter = new QuestionAdapter(getApplicationContext(), questionList, new QuestionAdapter.OnItemListener() {
        @Override
        public void onItemSelect(int position) {
           if (position+1==currentQuestion.getAnswerNB()){
               score++;
               tvScore.setText("Score: " + score);
           }
        }
        });
    showSolution();
}

现在我应该如何处理我的 showSolution 方法？似乎在 checkAnswer 之后我应该将信息发送回 QuestionAdapter 并在那里执行 setTextColor 。可能我走错了路......

Answer 1

你可以通过使用界面来做到这一点。

像这样创建一个接口(interface):

public interface OnItemListener {
    public void onItemSelect(int position);
}

然后在您的适配器中像这样更改构造函数:

  QuestionAdapter(Context mContext, ArrayList<Question> questionList, OnItemListener 
  onItemListener) {
        this.onItemListener = onItemListener;
        this.questionList = questionList;
    }

并将这一行添加到您的 onCheckedChangeListener

            onItemListener.onItemSelect(position);

像这样:

holder.rbGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(RadioGroup radioGroup, @IdRes int i) {

        // How can I handle Check status here and pass it to main activity?
        onItemListener.onItemSelect(position);
        }
    });

然后在你的 Activity 中添加这个你定义适配器的地方(这是定义适配器的另一种方式，你也可以使用你自己的方式只记得像这样添加接口(interface)(新的 OnItemListener ...)):

 dbHelper = new QuizDbHelper(getApplicationContext(), questionList, new 
 OnItemListener({

            @Override
            public void onItemSelect(int position) {
             // handle your check state of adapter item here
            }

        });