动态设置布局边距

Question

我有一个包含10个相对布局的垂直布局。 UX团队准备了一个水平线背景，所以我必须在屏幕上动态调整10个相对布局元素。 我编写了以下代码来设置一个监听器来获取垂直布局高度，然后进行计算。问题是我的高度值为-2。

    final LinearLayout layout = (LinearLayout) findViewById(R.id.fav_layout);
    final Context context = this;
    ViewTreeObserver vto = layout.getViewTreeObserver();
    vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

        @Override
        public void onGlobalLayout() {

            LinearLayout.LayoutParams params = (LinearLayout.LayoutParams)layout.getLayoutParams();
            int height = params.height;
            if (height <= 0)
                Toast.makeText(context, "measure < 0", Toast.LENGTH_SHORT).show();
            else {
                int count = layout.getChildCount();
                for (int i=0; i<count; i++){
                    RelativeLayout l = (RelativeLayout) layout.getChildAt(i);
                    RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);

                    lp.setMargins(10, height/10, 0, 0);

                    l.setLayoutParams(lp);
                }       
            }
        }

    });