javascript - scrollify 禁用向上滚动

Question

我尝试使用 scrollify 禁用向上滚动，我尝试使用此代码段但它不起作用

$(window).scroll(function () {
  var iCurScrollPos = $(this).scrollTop();
  if (iCurScrollPos > iScrollPos) {
    if($.scrollify.isDisabled()) {
   $.scrollify.enable()

    }
    console.log('down')
  } else {
    console.log('up');
   $.scrollify.disable()

  }
    iScrollPos = iCurScrollPos;
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>