鼠标滚轮事件（mousewheel、DOMMouseScroll）

 1 (function() {
 2     function handleMouseWheel(event) {
 3         event = EventUtil.getEvent(event);
 4         var delta = EventUtil.getWheelDelta(event);
 5         console.log(delta);
 6     }
 7 
 8     EventUtil.addHandler(document, "mousewheel", handleMouseWheel);
 9     EventUtil.addHandler(document, "DOMMouseScroll", handleMouseWheel);
10 })();