onscroll

问题 I\'ve a ListView displaying some items. I\'d like to perform some operation on the items that are currently displayed in the visible portion of the ListView , depending on how the ListView has been scrolled; thus I thought to implements the OnScrollListener of the ListView . Accordingly to the Android api reference, the onScroll method \"will be called after the scroll has completed\". This seems to me right what I needed, as once the scroll has completed, I perform my actions on the ListView

问题 So I am trying to use the JavaScript on scroll to call a function. But I wanted to know if I could detect the direction of the the scroll without using jQuery. If not then are there any workarounds? I was thinking of just putting a \'to top\' button but would like to avoid that if I could. I have now just tried using this code but it didn\'t work: if document.body.scrollTop <= 0 { alert (\"scrolling down\") } else { alert (\"scrolling up\") } 回答1: It can be detected by storing the previous