Method not getting called in android

Question

Code:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.taking_quiz);

    que = (TextView) findViewById(R.id.txtQuestion);
    opt1 = (Button) findViewById(R.id.button1);
    opt2 = (Button) findViewById(R.id.button2);
    opt3 = (Button) findViewById(R.id.button3);
    opt4 = (Button) findViewById(R.id.button4);
    qn = (TextView) findViewById(R.id.number);
    sco = (TextView) findViewById(R.id.score);
    qn.setText("1");
    sco.setText("Score : 0");
    qn.setText("Question : 1");

    RecieversId = getIntent().getStringExtra("Recievers_Id");

    mAuth = FirebaseAuth.getInstance();
    currentUser = mAuth.getCurrentUser();
    mDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users").child(RecieversId).child("Quiz").child("Question" + mQuestionNumber);

    updateQuestion();

}

private void updateQuestion() {

    if (mDatabaseReference != null) {
        mDatabaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                String question = dataSnapshot.child("Question").getValue().toString();
                answer = dataSnapshot.child("Answer").getValue().toString();
                option1 = dataSnapshot.child("Option1").getValue().toString();
                option2 = dataSnapshot.child("Option2").getValue().toString();
                option3 = dataSnapshot.child("Option3").getValue().toString();
                option4 = dataSnapshot.child("Option4").getValue().toString();
                que.setText(question);
                opt1.setText(option1);
                opt2.setText(option2);
                opt3.setText(option3);
                opt4.setText(option4);
            }
            @Override
            public void onCancelled(DatabaseError databaseError) {
            }
        });

        opt1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (option1.equals(answer)) {
                    opt1.setBackgroundColor(Color.GREEN);
                    mScore++;
                    sco.setText("Score : " + mScore);
                } else
                    opt1.setBackgroundColor(Color.RED);
                sco.setText("Score : " + mScore);
                final Handler handler = new Handler();
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        mQuestionNumber++;
                        qn.setText("Question : " + mQuestionNumber);
                        updateQuestion();
                        opt1.setBackgroundColor(Color.CYAN);
                    }
                }, 1500);
            }
        });
        opt2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (option2.equals(answer)) {
                    opt2.setBackgroundColor(Color.GREEN);
                    mScore++;
                    sco.setText("Score : " + mScore);
                } else
                    opt2.setBackgroundColor(Color.RED);
                sco.setText("Score : " + mScore);
                final Handler handler = new Handler();
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        mQuestionNumber++;
                        qn.setText("Question : " + mQuestionNumber);
                        updateQuestion();
                        opt2.setBackgroundColor(Color.CYAN);
                    }
                }, 1500);
            }
        });
        opt3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (option3.equals(answer)) {
                    opt3.setBackgroundColor(Color.GREEN);
                    mScore++;
                } else
                    opt3.setBackgroundColor(Color.RED);
                sco.setText("Score : " + mScore);
                final Handler handler = new Handler();
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        mQuestionNumber++;
                        qn.setText("Question : " + mQuestionNumber);
                        updateQuestion();
                        opt3.setBackgroundColor(Color.CYAN);
                    }
                }, 1500);
            }
        });
        opt4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (option4.equals(answer)) {
                    opt4.setBackgroundColor(Color.GREEN);
                    mScore++;
                    sco.setText("Score : " + mScore);
                } else
                    opt4.setBackgroundColor(Color.RED);
                sco.setText("Score : " + mScore);
                final Handler handler = new Handler();
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        mQuestionNumber++;
                        qn.setText("Question : " + mQuestionNumber);
                        updateQuestion();
                        opt4.setBackgroundColor(Color.CYAN);
                    }
                }, 1500);
            }
        });
    } else {
        Intent intent = new Intent(TakingQuiz.this, TakingQuizDone.class);
        intent.putExtra("Score", mScore);
        startActivity(intent);
    }
}

I'm trying to make a quiz app in Android using a firebase database.
When you click on one of the buttons (answer the question) the question number will increase and according to that question will also increase. But the ++ is working and the TextView which shows question number is showing that the question number is increasing but the question is not refreshing.
Like in the database I'm getting first question itself and the same options.
Here I guess the updateQuestion() method is not being called after buttonclick. please help

Database - https://ibb.co/emVEVo

Answer 1

It seems your firebase database reference (mDatabaseReference) is null so first of all check this. if it is not null then use debug log to check which line of code is not working .

Answer 2

好的，我发现了什么问题...我已经在onCreate而不是方法内部初始化了数据库引用...对不起，麻烦

Answer 3

Your Firebase Database Reference is getting the wrong tree.
In your image have more more fathers before " Quiz ", there's VwtdCRK... before and other...
When you use FirebaseDatabase.getInstance().getReference() it takes the root of your database. Should be like:

FirebaseDatabase.getInstance().getReference().child("rootNotShowingInimage")
    .child("VwtdCRK0AXQ2bnKe01fy8mYUPqs2").child("Quiz").child("Question"...