VisibilityChange事件;用于用户是否离开当前页面//页面的visibilityState属性可能返回三种状态:prerender、visible和hidden//监听可见性变化事件document.addEventListener('visibilitychange',function(){//被触发当页面变为不可见时if(document.visibilityState=='hidden'){document.title='Leave';}//当页面变为可见时触发if(document.visibilityState=='visible'){document.title='返回';}});//页面的隐藏属性,false,true;document.addEventListener('visibilitychange',function(){varisHidden=document.hidden;if(isHidden){document.title='离开';}else{document.title='回来';}});
