弹窗弹出时底部视图被覆盖

[javaCR7]

contentView 无法设置为RecyclerView.所以做了如下设置：
TextView contentView = new TextView(mActivityContext);
// recyclerView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
contentView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 0));
contentView.setText("");
contentView.setGravity(Gravity.CENTER);
contentView.setTextSize(TypedValue.COMPLEX_UNIT_SP, 20);
将高度设置0隐藏，但是下拉选择框时完全覆盖了底层的视图。点击弹窗时如何保持不覆盖掉全部？