iframe无滚动条，内容可滚动

不跨域情况下给iframe加载的document添加mousewheel事件，自己设置document.body/document.documentElement的scrollTop进行滚动

跨域没搞。。只能设置scrolling="auto"或者yes

<iframe scrolling="no" style="width:100%;height:300px;border:solid 1px #000" src="x.html" onload="bindMouseWhee(this)"></iframe>
<script>
    var  firefox = navigator.userAgent.indexOf('Firefox') != -1;
    function MouseWheel(e,doc) {
        e.preventDefault && e.preventDefault(), e.returnValue = false;
        var up = firefox && e.detail < 0 || e.wheelDelta > 0;

        doc.body.scrollTop = doc.documentElement.scrollTop += up ? -50 : 50;//每次滚动50px
    }
    function bindMouseWhee(ifr) {
        try {
            var  doc = ifr.contentWindow.document;
            firefox ? doc.addEventListener('DOMMouseScroll', function (e) { MouseWheel(e,doc)}, false) : (doc.onmousewheel = function (e) {MouseWheel(e||ifr.contentWindow.event,doc) });
        }
        catch (e) { alert('跨域无法获取iframe加载document'+e)}
    }
</script>