requestAnimationFrame作用与setTimeInterval类似,但是它会根据浏览器的刷新频率自动调整动画的时间间隔。
requestAnimationFrame兼容处理如下
if (!window.requestAnimationFrame) {
window.requestAnimationFrame = (window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
window.oRequestAnimationFrame ||
window.msRequestAnimationFrame ||
function (callback) {
return window.setTimeout(callback, 1000 / 60);
});
}