如何修改布局组件宽度设置固定值，在代码中动态修改

RelativeLayout.LayoutParams p1 = new RelativeLayout.LayoutParams(
                    RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
         p1.addRule(RelativeLayout.CENTER_VERTICAL);
         countview.setText(R.string.chat_broadcast_member_list);
         countview.setLayoutParams(p1);
         countview.setMaxWidth((int) (CommonUtil.getSystemWidth(this) * 0.70));
         countview.setPadding(0, 0, 6, 0);