如何将无线电组值从片段传递到 activity？

Question

如何从片段中的无线电组中获取值，我有 1 个片段来显示问题，我想获得值用户 activity 回答，因为下一步和后退按钮在 activity，我来自 sqlite 数据库的问题

我的activity片段

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);



    viewPager = findViewById(R.id.view_pager);
    setupViewPager(viewPager);

    back = findViewById(R.id.btnBack);
    next = findViewById(R.id.btnNext);
    back.setOnClickListener(this);
    next.setOnClickListener(this);
}

显示来自框架的问题 activity 使用 ViewPager

 private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());

        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(0));, "1");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(1));, "2");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(2);, "3");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(3));, "4");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(4));, "5");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(5);, "6");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(6));, "7");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(7));, "8");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(8));, "9");
        adapter.addFrag(QuestionFragment.newInstance(String.valueOf(9));, "10");
        viewPager.setOffscreenPageLimit(adapter.getCount());
        viewPager.setAdapter(adapter);
    }

下一步和返回按钮

@Override
public void onClick(View view) {
    if(view == back){
        mfragmentIndex--;
        viewPager.setCurrentItem(mfragmentIndex);


    }else if(view == next) {
            mfragmentIndex++;
            viewPager.setCurrentItem(mfragmentIndex);

    }
}

class 查看寻呼机

class ViewPagerAdapter extends FragmentPagerAdapter{
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitle = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

    @Override
    public int getCount() {
        return mFragmentList.size();
    }
    public void addFrag(Fragment fragment,String title){
        mFragmentList.add(fragment);
        mFragmentTitle.add(title);
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        return super.getPageTitle(position);
    }
}

我的片段显示问题

public static QuestionFragment newInstance(String questionId1) {
    final QuestionFragment fragment = new QuestionFragment();
    final Bundle args = new Bundle();
    args.putString(ARG_QUESTION_ID,questionId1);
    fragment.setArguments(args);
    return fragment;
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    final String question1 = getArguments().getString(ARG_QUESTION_ID);
    final DBAdapter dbAdapter = new DBAdapter(getContext());
    questionsList = dbAdapter.getAllQuestions();
    currentQuestion = questionsList.get(Integer.parseInt(question1));
    View view = inflater.inflate(R.layout.fragment_question, container, false);
    final RadioGroup grp=view.findViewById(R.id.radioGroup1);

    txtQuestion=view.findViewById(R.id.tvQuestion);
    rbtnA=view.findViewById(R.id.radio0);
    rbtnB=view.findViewById(R.id.radio1);
    rbtnC=view.findViewById(R.id.radio2);
    rbtnD=view.findViewById(R.id.radio3);
    setPertanyaan();
    return view;
}
private void setPertanyaan()
{

    txtQuestion.setText(currentQuestion.getQUESTION());
    rbtnA.setText(currentQuestion.getOptionA());
    rbtnB.setText(currentQuestion.getOptionB());
    rbtnC.setText(currentQuestion.getOptionC());
    rbtnD.setText(currentQuestion.getOptionD());
}

Answer 1

可以通过在片段 class 中创建接口然后在 activity 中实现它来完成。

在片段中创建一个接口，如：-

// Container Activity must implement this interface
public interface OnRadioGroupSelectedListener {
    public void onButtonSelected(String value);
}

在片段class中全局声明listner对象：-

OnRadioGroupSelectedListener mCallback;

Fragment 在其 onAttach() 生命周期方法中捕获接口实现，然后可以调用接口方法以便与 Activity.

通信

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);

    // This makes sure that the container activity has implemented
    // the callback interface. If not, it throws an exception
    try {
        mCallback = (OnRadioGroupSelectedListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement OnRadioGroupSelectedListener");
    }
}

现在接收回调添加：-

radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener()
{
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        // checkedId is the RadioButton selected
       // if(checkedId==R.id.radio0)  {
      //      mCallback.onButtonSelected(0)
       //  }else if (checkedId==R.id.radio1)  {
       //     mCallback.onButtonSelected(1);

       //  }else if (checkedId==R.id.radio2)  {
        //      mCallback.onButtonSelected(2);

       //  }else if (checkedId==R.id.radio3)  {
       //     mCallback.onButtonSelected(3);

       //  }
     RadioButton radioButton = group.findViewById(checkedId);

     mCallback.onButtonSelected(radioButton.getText());


});

回调将选中的单选按钮的位置传递给 activity。

现在 activity 实现列表器，

implements QuestionFragment.OnRadioGroupSelectedListener

并覆盖方法以获取 activity 中选定的按钮位置。

注意：- 您还可以根据需要更改 onButtonSelected(String selectedRadioButtonValue) 参数。

如何将无线电组值从片段传递到 activity？

how to pass a radiogroup value from a fragment to an activity?

android

android-fragments

android-radiogroup