动态添加TextView背景图片，背景不改变大小

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
ViewGroup.LayoutParams.WRAP_CONTENT);

    for (int i = 0; i < name.length; i++) {
        TextView textView = new TextView(getActivity());
        layoutParams.setMargins(10, 0, 0, 0);
        textView.setTextSize(20);
        textView.setBackgroundResource(R.drawable.im_number); //设置背景
        textView.setText(name[i]);
        textView.setGravity(Gravity.CENTER);
        textView.setLayoutParams(layoutParams);
        llNumber.addView(textView);
                    需求是这样的，我要添加多个texitview而且要添加背景，但是添加背景不随textview的增多而变小，就显示不玩了，要怎么让背景图片跟随着变化？