@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec); //获取SingleTouchView所在父布局的中心点
ViewGroup mViewGroup = (ViewGroup) getParent();
if(null != mViewGroup){
mParentWidth = mViewGroup.getWidth();
mParentHeight = mViewGroup.getHeight();
} }