1.通过findViewById得到xml中的控件；

2.通过当前控件的getLayoutParams()得到它的LayoutParams；

3.设置params的自定义宽高；

4.控件调用setLayoutParams改变原有宽高

例如：

titleLayout = (RelativeLayout) findViewById(R.id.rl_msg); RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) titleLayout.getLayoutParams(); params.height = (int)(dm.heightPixels/12.8); titleLayout.setLayoutParams(params);