怎么使用JavaScript检测CSS转换何时结束

function gettransitionend(){

var root = document.documentElement

var transitions = {

'transition':'transitionend',

'OTransition':'oTransitionEnd',

'MozTransition':'transitionend',

'WebkitTransition':'webkitTransitionEnd'

}

for (var t in transitions){

if (root.style[t] !== undefined ){

return transitions[t];

}

}

return undefined

}

//Example Usage:

var transitionendevt = gettransitionend()

if (transitionendevt){ // if transitionend event supported by browser

element.addEventListener(transitionendevt, function(e){

// do something after end of transition

}, false)

}