显示、隐藏某个布局或者控件

    btn_dp.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                num++;
                if (num % 2 == 0) {
                    dp_lv.setVisibility(View.GONE);
                } else {
                    dp_lv.setVisibility(View.VISIBLE);
                }
            }
        });