Android 代码设置RelativeLayout元素居中

1. RelativeLayout relativeLayout= new RelativeLayout(this);

1. RelativeLayout.LayoutParams rlp=new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,RelativeLayout.LayoutParams.WRAP_CONTENT);
2. rlp.addRule(RelativeLayout.CENTER_IN_PARENT);//addRule参数对应RelativeLayout XML布局的属性
3. relativeLayout.addView(progressBar,rlp);