如何跨浏览器标准化CSS3 Transition功能？

Modernizr中使用了一项技术，对它进行了改进：

function transitionEndEventName () {    var i,        undefined,        el = document.createElement('div'),        transitions = { 'transition':'transitionend', 'OTransition':'otransitionend',  // oTransitionEnd in very old Opera 'MozTransition':'transitionend', 'WebkitTransition':'webkitTransitionEnd'        };    for (i in transitions) {        if (transitions.hasOwnProperty(i) && el.style[i] !== undefined) { return transitions[i];        }    }    //TODO: throw 'TransitionEnd event is not supported in this browser'; }

然后，只要需要过渡结束事件，就可以调用此函数：

var transitionEnd = transitionEndEventName();element.addEventListener(transitionEnd, theFunctionToInvoke, false);