function openIos(url, callback) {

    if (!url) {

        return;

    }

    var node = document.createElement('iframe');

    node.style.display = 'none';

    var body = document.body;

    var timer;

    var clear = function(evt, isTimeout) {

       (typeof callback==='function') &&  callback(isTimeout);

        window.removeEventListener('pagehide', hide, true);

        window.removeEventListener('pageshow', hide, true);

        if (!node) {

            return;

        }

        node.onload = null;

        body.removeChild(node);

        node = null;

    };

    var hide = function(e){

        clearTimeout(timer);

        clear(e, false);

    };

    window.addEventListener('pagehide', hide, true);

    window.addEventListener('pageshow', hide, true);

    node.onload = clear;

    node.src = url;

    body.appendChild(node);

    var now = +new Date();

    //如果事件失败，则1秒设置为空

    timer = setTimeout(function(){

        timer = setTimeout(function(){

          var newTime = +new Date();

          if(now-newTime>1300){

            clear(null, false);

          }else{

            clear(null, true);

          }

        }, 1200);

    }, 60);

}