js 判断用户是否在浏览当前页面

 1 var hiddenProperty = ‘hidden‘ in document ? ‘hidden‘ :    
 2     ‘webkitHidden‘ in document ? ‘webkitHidden‘ :    
 3     ‘mozHidden‘ in document ? ‘mozHidden‘ :    
 4     null;
 5 var visibilityChangeEvent = hiddenProperty.replace(/hidden/i, ‘visibilitychange‘);
 6 var onVisibilityChange = function(){
 7     if (!document[hiddenProperty]) {    
 8         console.log(‘页面非激活‘);
 9     }else{
10         console.log(‘页面激活‘)
11     }
12 }
13 document.addEventListener(visibilityChangeEvent, onVisibilityChange);