Android RelativeLayout 用纯java设置margin的办法

      RelativeLayout rl =    new RelativeLayout(this);     

            

            MarginLayoutParams mp = new MarginLayoutParams(20,20);  //item的宽高

            mp.setMargins(0, 0, 25, 0);//分别是margin_top那四个属性

            RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(mp);

            lp.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);

            

            Button bt = new Button(this);

            bt.setLayoutParams(lp);

            

            rl.addView(bt);