ios设备中angularjs无法改变页面title的解决方法

$rootScope.$watch('title',function(title){ var body = document.getElementsByTagName('body')[0]; document.title = title; var iframe = document.createElement("iframe"); iframe.title = ''; iframe.width = 0; iframe.height = 0; iframe.setAttribute("src", "/empty.png"); iframe.addEventListener('load', function() { setTimeout(function() {  iframe.removeEventListener('load');  document.body.removeChild(iframe); }, 0); }); document.body.appendChild(iframe);});