我正在处理一个带有固定菜单的页面,该菜单在用户从顶部滚动一定距离后拾取,当它们向下滚动页面时,菜单中的不同链接将被赋予一个更改颜色的类.所有这一切似乎都适用于Chrome和Safari,但在Firefox中,页面冻结在顶部.我想知道它是否在不断地循环一些代码……基本上冻结了窗口.
这是我的代码.
$.localScroll({
onBefore: function() {
$('body').data('scroll-executing',true);
},onAfter: function() {
$('body').data('scroll-executing',false);
$(window).trigger("scroll");
}
});
$(window).scroll(function () {
if ($(this).scrollTop() > 259) {
$('.nav').addClass("f-nav");
} else {
$('.nav').removeClass("f-nav");
}
});
$(window).scroll(function() {
if ($('body').data('scroll-executing')) {
return;
}
// find the a with class 'active' and remove it
$("a").removeClass('active');
// get the amount the window has scrolled
var scroll = $(window).scrollTop();
// add the 'active' class to the correct #nav based on the scroll amount
if (scroll > 2150) {
$("#nav_3").removeClass('active');
$("#nav_5").attr('class','active');
setHash("contact");
} else if (scroll > 1300) {
$("#nav_2").removeClass('active');
$("#nav_3").attr('class','active');
setHash("portfolio");
} else if (scroll > 400) {
$("#nav_2").attr('class','active');
setHash("about");
} else if (scroll <= 380) { //when I remove this section,the problem goes away.
$("#nav_1").attr('class','active');
setHash("home");
}
});
我忘了添加setHash定义.这里是.
setHash = function(hash) {
var scrollmem = $('body').scrollTop();
window.location.hash = hash;
$('html,body').scrollTop(scrollmem);
}
我也注意到cpu上升到100％,我似乎无法弄清楚原因.
问题出现在以else开头的代码的第三部分if(scroll< = 380).我通过消除过程想出来了.任何人都可以看到它循环或做一些永远不会结束的事情......或者会解释为什么firefox冻结在页面顶部？ 我对这一切都很陌生……在过去的几天里我只是选择了jquery,我基本上都在谷歌上搜索并调整代码以使其符合我的需要. 任何帮助将非常感激.
http://documentcloud.github.com/underscore/#throttle
It’s a very,very,bad idea to attach handlers to the window scroll event. Depending upon the browser the scroll event can fire a lot and putting code in the scroll callback will slow down any attempts to scroll the page (not a good idea). Any performance degradation in the scroll handler(s) as a result will only compound the performance of scrolling overall. Instead it’s much better to use some form of a timer to check every X milliseconds OR to attach a scroll event and only run your code after a delay (or even after a given number of executions – and then a delay).
07001
