scroll-view需要设定一个准确的高，但是子元素有个下拉加载，无法确定高度，设定为100%sroll事件不生效怎么解决

问题相关代码，请勿粘贴截图

<scroll-view 
class='page-container' 
style=" overflow-y: scroll;" 
refresher-enabled="{{scroll_refresher_enabled}}" 
refresher-threshold="50" 
bindrefresherrefresh="onRefresh" 
refresher-triggered="{{triggered}}" 
bindtouchstart='changeNavbar' 
bindscroll="scrollMOve" 
scroll-y="{{true}}"
scroll-top='{{topNum}}'>

对应位置加一个占位元素，存储对应的Rect，比较scrollTop 与React.top