preventing a user from entering multiple answer

Question

i create a true/false quiz app. in that app i have 4 buttons ie True,False,previous(to get back to previous question),next(to get the next question). i want to add a functionality when a user click on true or false button its get disable for that question so the user can click only once for one question.

i tried to disable the button by using button.setEnabled(false) but when i click on previous button or next button the true/false buttons enabled.i want that the user can click the answer only once it does not matter how much the user traverse the question.

i try to call the setEnabledButton() in previous on click button but it disable the button but it also disable whether the user click on answer or not.

Button btrue,bfalse,bnext,bprevious;
TextView tquestion;
int mCurrentIndex=0;
Questions[] questionbank;

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

    btrue=findViewById(R.id.true_button);
    bfalse=findViewById(R.id.false_button);
    bnext=findViewById(R.id.next_button);
    tquestion=findViewById(R.id.question_text);
    bprevious=findViewById(R.id.previous_button);


    questionbank = new Questions[]
             {

                new Questions(R.string.greater,false),
                     new Questions(R.string.Pm,true),
                     new Questions(R.string.capital,true),
                     new Questions(R.string.china,false),
                     new Questions(R.string.Richer,false),
                     new Questions(R.string.company,true),
                     new Questions(R.string.company1,false),

             };


         update();

         bnext.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            int s=questionbank.length;
            if( mCurrentIndex<=s  )
                {
                    if (mCurrentIndex + 1 < questionbank.length) {
                        mCurrentIndex++;

                    }
                    else
                    {   Toast.makeText(getApplicationContext(),"not more question",Toast.LENGTH_SHORT).show();
                    }
                    update();

            }
        }
    });


    btrue.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            checkAnswer(true);

        }
    });

    bfalse.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
               checkAnswer(false);
        }
    });

    bprevious.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (mCurrentIndex > 0) {
                mCurrentIndex = (mCurrentIndex - 1);
                update();
            }
            else
                { Toast.makeText(getApplicationContext(), "cant go back", Toast.LENGTH_SHORT).show(); }

        }
    });

}

public void update()
{
    int ques = questionbank[mCurrentIndex].getmTextResid();
      tquestion.setText(ques);
      setButtonEnabled(true);

}

private void checkAnswer(boolean userPressedTrue)
{
    boolean answerIsTrue =
            questionbank[mCurrentIndex].ismTrueAnswer();
    int messageResId = 0;
    if (userPressedTrue == answerIsTrue) {
        setButtonEnabled(false);
        messageResId = R.string.correct_toast;
    } else {
        setButtonEnabled(false);
        messageResId = R.string.incorrect_toast;
    }
    Toast.makeText(this, messageResId,
            Toast.LENGTH_SHORT)
            .show();
}

private void setButtonEnabled(boolean enabled) {

    btrue.setEnabled(enabled);
    bfalse.setEnabled(enabled);
}

}

Answer 1

In Questions class you can create a method,

public class Questions {

    boolean isQuestionAnswered;

    public boolean isQuestionAnswered() {
        return isQuestionAnswered;
    }

    public void setQuestionAnswered(boolean questionAnswered) {
        isQuestionAnswered = questionAnswered;
    }
}

private void checkAnswer(boolean userPressedTrue)
{
    questionbank[mCurrentIndex].setQuestionAnswered(true);    
    boolean answerIsTrue =
            questionbank[mCurrentIndex].ismTrueAnswer();
    int messageResId = 0;
    if (userPressedTrue == answerIsTrue) {
        setButtonEnabled(false);
        messageResId = R.string.correct_toast;
    } else {
        setButtonEnabled(false);
        messageResId = R.string.incorrect_toast;
    }
    Toast.makeText(this, messageResId,
            Toast.LENGTH_SHORT)
            .show();
}

public void update()
{
    int ques = questionbank[mCurrentIndex].getmTextResid();
      tquestion.setText(ques);
      if(questionbank[mCurrentIndex].isQuestionAnswered())
        setButtonEnabled(false);
      else
        setButtonEnabled(true);

}

Try this out and check whether this solves your problem