监听返回按钮以及关闭微信内置浏览器

$(function(){
        pushHistory();
        window.addEventListener("popstate", function(e) {
            if(${photo != null}) {
                /*返回前三个页面*/
                setTimeout('WeixinJSBridge.call("closeWindow")',2000);
            }else{
                /*返回上一个页面*/
                setTimeout('WeixinJSBridge.call("closeWindow")',2000);
            }
        }, false);
        function pushHistory() {
            var state = {
                title: "title",
                url: "#"
            };
            window.history.pushState(state, "title", "#");
        }
    });