"在Android中以编程方式将按钮放在彼此下方？"

Question

我想在彼此下方放置一些按钮。 我试过这样：

View previousView =null;
            RelativeLayout evaluationSections = findViewById(R.id.evaluation_sections);
            for (int i = 0; i < getQuestions().length(); i++) {
                Button question = new Button(activity);
                RelativeLayout.LayoutParams questionLayoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
                if (previousView != null){
                    questionLayoutParams.addRule(RelativeLayout.BELOW,previousView.getId());
                }
                question.setLayoutParams(questionLayoutParams);
                question.setId(ViewCompat.generateViewId());
                question.setText("Question "+i);
                evaluationSections.addView(question);
                previousView = question;

                for (int j=0;j< getAnswers().length();j++){
                    Button answer = new Button(activity);
                    RelativeLayout.LayoutParams answerLayoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
                    answer.setText("Answer "+j);
                    if (previousView != null){
                        answerLayoutParams.addRule(RelativeLayout.BELOW,previousView.getId());
                    }
                    answer.setLayoutParams(answerLayoutParams);

                    evaluationSections.addView(answer);

                    previousView = answer;
                    
                }

按钮彼此重叠，但应在彼此下方。 您知道它不起作用的原因是什么吗？