Android 利用layoutParams代码动态设置布局位置

FrameLayout下动态设置子控件居中，动态用JAVA代码要这样实现:

FrameLayout.LayoutParams lytp = new FrameLayout.LayoutParams(80,LayoutParams.WRAP_CONTENT);
lytp .gravity = Gravity.CENTER;
btn.setLayoutParams(lytp);

 

RelativeLayout下动态设置子控件居中：

RelativeLayout.LayoutParams lp=new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT); 
lp.addRule(RelativeLayout.ALIGN_PARENT_RIGHT, RelativeLayout.TRUE); 
lp.addRule(RelativeLayout.ALIGN_PARENT_TOP, RelativeLayout.TRUE); 
btn1.setLayoutParams(lp);