android setLayoutParams不起作用

手动添加radiobutton，这样写无marginTop效果

RadioGroup.LayoutParams bt_params = new RadioGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ScreenUtil.dp2px(50,this));
bt_params.setMargins(0,ScreenUtil.dp2px(10,this),0,0);

radioButton.setLayoutParams(bt_params);

radioGroup.addView(radioButton);

把setLayoutParams()放到addView之后，就有效果

RadioGroup.LayoutParams bt_params = new RadioGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ScreenUtil.dp2px(50,this));
bt_params.setMargins(0,ScreenUtil.dp2px(10,this),0,0);

radioGroup.addView(radioButton);

radioButton.setLayoutParams(bt_params);