翻译:《Everything You Need to Know About the CSS will-change Property》- 7
// Rough generic example
// Get the element that is going to be animated on click, for example
var el = document.getElementById('element');
// Set will-change when the element is hovered
el.addEventListener('mouseenter', hintBrowser);
el.addEventListener('animationEnd', removeHint);
function hintBrowser() {
// The optimizable properties that are going to change
// in the animation's keyframes block
this.style.willChange = 'transform, opacity';
}
function removeHint() {
this.style.willChange = 'auto';
}