cocos2dx scrollview将选中项移动到视图中间位置

//Inner的最小Y值
			float minY = m_listIndex->getContentSize().height - m_listIndex->getInnerContainerSize().height;
			//Inner超出部分的高度
			float h = -minY;

			//选中项对应view的位置
			//float viewY = (btn->getPositionY()) + m_listIndex->getInnerContainerPosition().y;
			//inner的目标位置即选中项移动到view中间的位置
			float innerTargetY = m_listIndex->getContentSize().height / 2 - btn->getPositionY();
			if (innerTargetY > 0)
				innerTargetY = 0;
			if (innerTargetY < minY)
				innerTargetY = minY;
			//m_listIndex->getInnerContainer()->setPositionY(innerTargetY);
			float percent = 100 - abs(innerTargetY) / h * 100;
			m_listIndex->scrollToPercentVertical(percent, PublicData::s_fIndexDuration, true);