pushHistory(); 
    window.addEventListener("popstate", function(e) { 
      window.location = 'http://www.baidu.com';
    }, false); 
    function pushHistory() { 
      var state = { 
        title: "title", 
        url: "#"
      }; 
      window.history.pushState(state, "title", "#"); 
    }

/**
 * 使用 HTML5 的 History 新 API pushState 來(lái)曲線監(jiān)聽(tīng) Android 設(shè)備的返回按鈕
 * XBack.listen(function(){
    alert('oh! you press the back button');
  });
 */
;!function(pkg, undefined){
  var STATE = 'x-back';
  var element;
  var onPopState = function(event){
    event.state === STATE && fire();
  }
  var record = function(state){
    history.pushState(state, null, location.href);
  }
  var fire = function(){
    var event = document.createEvent('Events');
    event.initEvent(STATE, false, false);
    element.dispatchEvent(event);
  }
  var listen = function(listener){
    element.addEventListener(STATE, listener, false);
  }
  ;!function(){
    element = document.createElement('span');
    window.addEventListener('popstate', onPopState);
    this.listen = listen;
    record(STATE);
  }.call(window[pkg] = window[pkg] || {});
}('XBack');

XBack.listen(function(){
  alert('back');
});