底部显示隐藏时机

src/pages/home/index.vue

@@ -277,10 +277,10 @@ export default {
         (delta>0 && showFlag=='down') ||
         (delta<0 && showFlag=='up')
         ){
+        this.beforeScrollTop = afterScrollTop;
          return;
       }
       this.$mp.page.getTabBar().setData({'showFlag':delta>0?'down':'up'})
-      this.beforeScrollTop = afterScrollTop;
     },
     scrolltolower(){
       console.log("scrolltolower")