如何防止文档滚动但允许iOS和Android网站上的div元素滚动？

终于，我开始工作了。真的很简单：

var $layer = $("#layer");$layer.bind('touchstart', function (ev) {    var $this = $(this);    var layer = $layer.get(0);    if ($this.scrollTop() === 0) $this.scrollTop(1);    var scrollTop = layer.scrollTop;    var scrollHeight = layer.scrollHeight;    var offsetHeight = layer.offsetHeight;    var contentHeight = scrollHeight - offsetHeight;    if (contentHeight == scrollTop) $this.scrollTop(scrollTop-1);});