scroll-view組件里的屬性bindscroll。
鏈接: bindscroll.

//wxml
<scroll-view scroll-y bindscroll="bindscrollfx" class="videoList">
		//內容
</scroll-view>

// js
//判斷上下滾動方向）（deltaY小于0時，向下，向上則反之）
  bindscrollfx: function (e) {
    var that = this;
    console.log(e.detail.deltaY);
    var scrollfx=e.detail.deltaY;
    if(scrollfx<0){
      that.setData({
        istrue_scroll:false  //向下滾動
      })
    }else{
      that.setData({
        istrue_scroll:true
      })
    }         
  },