Android 如何在父控件的四個角落添加控件

在控件的四個角落添加子控件（左上角，右上角，左下角，右下角）

在RelativeLayout中有這麼幾種對齊方式

RelativeLayout.ALIGN_PARENT_BOTTOM  

RelativeLayout.ALIGN_PARENT_TOP 

RelativeLayout.ALIGN_PARENT_LEFT 

RelativeLayout.ALIGN_PARENT_RIGHT

So ,若是想在父控件的右下角添加控件

xxxViewGroup.addView(xxxView);

RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(); 

params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, RelativeLayout.TRUE);

params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE);

xxxView.setLayoutParams(params);