Styjun

How can I use Viewpager Adapter Button into MainActivity? I am developing a quiz app and I am comparing button value into MainActivity. How can I access ViewPagerAdapter class buttons In MainActivity?

@Override
 protected void onStart() {
 super.onStart();

 Ref.child("Exam_Category").child("PRACTICE TEST").child("PREVIOUS YEAR PAPER'S").child(ct1).child(ct2).child("ENGLISH COMPREHENSION").addValueEventListener(new ValueEventListener() 
 @Override
 public void onDataChange(@NonNull DataSnapshot dataSnapshot) 
 if (dataSnapshot.exists())
 for (DataSnapshot data : dataSnapshot.getChildren()) 
 key = data.getKey().toString();


 Ref.child("Exam_Category").child("PRACTICE TEST").child("PREVIOUS YEAR PAPER'S").child(ct1).child(ct2).child("ENGLISH COMPREHENSION").child(String.valueOf(key))
 .addValueEventListener(new ValueEventListener() 
 @Override
 public void onDataChange(@NonNull DataSnapshot dataSnapshot) 
 if (dataSnapshot.exists()) 
 final questions studentDetails = dataSnapshot.getValue(questions.class);
 list.add(studentDetails);

 adapter = new RecyclerViewAdapter(Previous_Yr_Quiz.this, list);

 viewPager.setAdapter(adapter);
 
 


 @Override
 public void onCancelled(@NonNull DatabaseError databaseError) 

 
 );

 
 

 //total_q.setText(Question_No +" / "+key);
 

 @Override
 public void onCancelled(@NonNull DatabaseError databaseError) 

 
 );

This is My ViewPager Adapter

public class RecyclerViewAdapter extends PagerAdapter 


 // Declare Variables
 Context context;
 LayoutInflater inflater;
 public List<questions> list;




 public RecyclerViewAdapter(Context context, List<questions> TempList) 
 this.context = context;

 this.list = TempList;
 

 @Override
 public int getCount() 
 return list.size();
 

 @Override
 public boolean isViewFromObject(View view, Object object) 
 return view == ((RelativeLayout) object);
 

 @Override
 public Object instantiateItem(ViewGroup container, final int position) 

 // Declare Variables
 TextView question;
 final Button option1,option2,option3,option4;


 inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 View itemView = inflater.inflate(R.layout.quiz_layout_listview, container,
 false);



 // Locate the TextViews in viewpager_item.xml
 question = (TextView)itemView.findViewById(R.id.question);
 option1 = (Button) itemView.findViewById(R.id.optiona);
 option2 = (Button) itemView.findViewById(R.id.optionb);
 option3 = (Button) itemView.findViewById(R.id.optionc);
 option4 = (Button) itemView.findViewById(R.id.optiond);





 // Capture position and set to the TextViews
 questions studentDetails = list.get(position);
 question.setText(studentDetails.getQuestion());
 option1.setText(studentDetails.getOption1());
 option1.setId(position);
 option2.setText(studentDetails.getOption2());
 option3.setText(studentDetails.getOption3());
 option4.setText(studentDetails.getOption4());



 option1.setOnClickListener(new View.OnClickListener() 
 @Override
 public void onClick(View v) 

 option1.setBackgroundResource(R.drawable.wrong);

 
 );

 ((ViewPager) container).addView(itemView);

 return itemView;


 






 @Override
 public void destroyItem(ViewGroup container, int position, Object object) 
 // Remove viewpager_item.xml from ViewPager
 ((ViewPager) container).removeView((RelativeLayout) object);



 

 private int getItem(int i) 
 return list.size();

 

How can used button options A, B, C, D OnClick in MainActivity because I compare button value into A, B, C, D buttons....

You have two options:

1) Make Buttons as class members and access them from your Activity by get methods.

2) Write an Interface that will have the callback methods so you know which Button is being clicked. Once you write the interface you pass it as a constructor parameter or by a set method. Something like:

interface QuizListener 
 void answered(Button whichButton);


...
[RecyclerViewAdapter.java]
public RecyclerViewAdapter(Context context, List<questions> TempList, QuizListener quizListener) 
 this.context = context;
 this.list = TempList;
 this.quizListener = quizListener;


...

option1.setOnClickListener(new View.OnClickListener() 
 @Override
 public void onClick(View v) 
 if (quizListener != null) 
 quizListener.answered(option1);
 
 option1.setBackgroundResource(R.drawable.wrong);
 
);