RelativeLayout不能调用measure去直接测量子元素

RelativeLayout在实现onMeasure方法时并没有像LinearLayout一样去重写如下代码：

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (mOrientation == VERTICAL) {
measureVertical(widthMeasureSpec, heightMeasureSpec);
} else {
measureHorizontal(widthMeasureSpec, heightMeasureSpec);
}
}