Как использовать Radiogroup с 4 различными кнопками радио в ArrayAdapter

Question

У меня есть пользовательский адаптер списка, который имеет вопрос в текстовом режиме и четыре варианта ответа в Radio Buttons. Все радио кнопки соединены вместе в Radio Group. Проблема в том, что я не могу отслеживать проверенные кнопки. При прокрутке кнопки проверяются случайным образом. Как я могу хранить переключатели, которые выбраны для конкретного

---

общественного класса MCQAdapter расширяет ArrayAdapter {

public MCQAdapter(Activity context, ArrayList<MCQ> mcq) { 
    super(context, 0, mcq); 
} 

@NonNull 
@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
    View listItemView = convertView; 

    if (listItemView == null) { 
     listItemView = LayoutInflater.from(getContext()).inflate(R.layout.activity_mcqlist, parent, false); 
    } 


    final MCQ currentContent = (MCQ) getItem(position); 
    TextView content = (TextView) listItemView.findViewById(R.id.Question_Block); 
    content.setText(currentContent.getQuestion()); 

    RadioGroup rg = (RadioGroup) listItemView.findViewById(R.id.Radio_Group); 

    final RadioButton rb1 = (RadioButton) listItemView.findViewById(R.id.Option1_Block); 
    rb1.setText(currentContent.getOptionA()); 

    final RadioButton rb2 = (RadioButton) listItemView.findViewById(R.id.Option2_Block); 
    rb2.setText(currentContent.getOptionB()); 

    final RadioButton rb3 = (RadioButton) listItemView.findViewById(R.id.Option3_Block); 
    rb3.setText(currentContent.getOptionC()); 

    final RadioButton rb4 = (RadioButton) listItemView.findViewById(R.id.Option4_Block); 
    rb4.setText(currentContent.getOptionD()); 

    return listItemView; 

} 

}

public class MCQ { 

String question,optionA,optionB,optionC,optionD,answer,userAnswer; 

public MCQ(String quest,String a,String b,String c, String d,String ans){ 

    question = quest; 
    optionA = a; 
    optionB = b; 
    optionC = c; 
    optionD = d; 
    answer = ans; 

} 

public String getQuestion(){ 
    return question; 
} 

public String getOptionA() { 
    return optionA; 
} 

public String getOptionB() { 
    return optionB; 
} 

public String getOptionC() { 
    return optionC; 
} 

public String getOptionD() { 
    return optionD; 
} 

public String getAnswer() { 
    return answer; 
} 

public String getUserAnswer() { 
    return userAnswer; 
} 

public void setUserAnswer(String userAnswer) { 
    this.userAnswer = userAnswer; 
} 

}

public class PropertiesOfConstructionMaterail extends AppCompatActivity { 

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

    final ArrayList<MCQ> mcq = new ArrayList<MCQ>(); 

    //Creating Different Instance Of MCQ to genarte various questions for Properties of Consrtuction Material 
    mcq.add(new MCQ("The property of material by which it can be beaten or rolled into thin plates, is called ?", 
      "Malleability","Ductility","Plasticity","Elasticity","Malleability")); 
    mcq.add(new MCQ("The property by which a body returns to its original shape after removal of the force, is called ?", 
      "Plasticity","Elasticity","Ductility","Malleability","Elasticity")); 
    mcq.add(new MCQ("The property of a material by which it can be drawn into smaller section due to tension, is called ?" 
      ,"Plasticity","Ductility","Elasticity","Malleability","Ductility")); 

MCQAdapter adapter = new MCQAdapter(this,mcq); 

    ListView listView = (ListView) findViewById(R.id.list); 
    listView.setAdapter(adapter); 
} 

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:id="@+id/activity_mcqlist" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
tools:context="com.example.silen.civilengineeringmcq.MCQList" 
android:orientation="vertical"> 

<TextView 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/Question_Block" 
    android:textSize="18dp" 
    android:textStyle="bold"/> 

<RadioGroup 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/Radio_Group"> 

    <RadioButton 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/Option1_Block" 
     android:checked="false"/> 

    <RadioButton 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/Option2_Block" 
     android:checked="false"/> 

    <RadioButton 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/Option3_Block" 
     android:checked="false"/> 

    <RadioButton 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/Option4_Block" 
     android:checked="false"/> 

</RadioGroup> 

Answer 1

Вы должны создать оболочку вокруг Pojo класса (MCQ), назовите его ViewModel, который хранит текущее состояние зрения внутри адаптера. В вашем случае это состояние является переключателем.

Это будет выглядеть так:

class ViewModel extends MCQ { 
    MCQ mcq; 

    int radioButtonSelectedId; 

    public ViewModel(MCQ mcq) { 
     this.mcq = mcq; 
     this.radioButtonSelectedId = R.id.Option1_Block; 
    } 

    public void setRadioButtonSelectedId(int id) { 
     this.id = id; 
    } 

    public int getRadioButtonSelectedId() { 
     return id; 
    } 

    //delegates to mcq getter/setter methods 
} 

Вашего getView метод:

public View getView(int position, View convertView, ViewGroup parent) { 
//your logic above 
    radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { 
      @Override 
      public void onCheckedChanged(RadioGroup group, int checkedId) { 
       viewModel.setRadioButtonSelectedId(checkedId); 
      } 
     }); 

    //same for other radio buttons 
    rb1.setChecked(viewModel.getRadioButtonSelectedId() == R.id.Option1_Block); 
//your logic below 
} 

Итак, как я упомянул выше, список массива внутри адаптера будет содержать ViewModel s оберток, а не MCQ классов непосредственно

final ArrayList<ViewModel> mcqList = new ArrayList<>(); 
MCQ mcq = new MCQ("The property of material by which it can be beaten or rolled into thin plates, is called ?", 
     "Malleability","Ductility","Plasticity","Elasticity","Malleability") 
mcqList.add(new ViewModel(mcq)); 

Я думаю, вы должны g et a option