h5手机返回按钮_关于h5开发的移动端页面，如何获取手机物理按键的返回功能来使页面作出逐步的后退...

(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('切换历史');

});