Question

在我的MainActivity方法中，必须修改checkAnswer和showSolution，因为我向项目添加了RecycleView适配器，并将所有视图项移至QuestionAdapter。我不明白如何在QuestionAdapter中使用isChecked检查rbGroup单选按钮的状态并将其ID传递给MainActivity。我尝试检查以下内容：Radiogroup in recyclerview 但是我仍然不清楚下一步该怎么做。有人可以给我基本的指导，从现在开始应该采取什么步骤来修改我的项目。在“回收”视图中仍找不到用于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？

根据建议进行了一些更新。不明白如何修改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");

}

QuestionAdapter

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。 在将接口添加到QuestionAdapter并对构造函数和其他部分进行更改后，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();
}

现在我应该如何使用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

您可以使用界面执行此操作。

创建这样的接口：

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

然后在适配器中按如下所示更改构造函数：

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

并将此行添加到您的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);
        }
    });

然后在您的活动中将其添加到您定义适配器的位置（这是定义适配器的另一种方式，您也可以使用自己的方式，只记得添加这样的接口（新的OnItemListener ...））：

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

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

        });

Answer 2

您可能想查看下面我写的有关处理适配器点击并将其委派给活动或片段的文章

https://medium.com/@pithadiyamitesh/adaptercallback-for-handling-item-clicks-on-list-items-in-android-4f731d7d0094

检查Recycle View Adapter中的单选按钮状态，并通过MainActivity对其进行更改

2 个答案: