The same old issue, .scrollTop(0) not working in C

问题:

First, let me point out, i've googled and even looked at answers on here like this and this, however, I'm still yet to find a working solution for my case.

I've designed a page that has several fixed elements covering the page and makes of html5/css3 to create a clean "mask" over the main document, thus allowing the body scroll bar to still scroll the underlying content.

In firefox and ie (bleh), scrollTop(0) is working perfect. However, as stated by the question, not so much in my fav browsers.

Something I've made note of is to call the following both before the scrollTo event and after

$("body,html,document").each(function(){ console.log($(this).scrollTop()); });

The results were not pleasing, it tells me that the scrolltop is already 0 and thus is not even attempting a scrollTop, or at least that's what I "think" thus far.

And before you ask, i made that console call on each of those 3 items as the document scrolltop should be covered within one of those items (i would think body, but like in ie you have to call html too)

Any takers on ideas?

FYI, it may be a css oddity (tho how it works in IE and not chrome i really cant understand) but I have already tried the following with negative results:

$(window).scrollTop(0);
$(document).scrollTop(0);
$("html").scrollTop(0);
$("body").scrollTop(0);
window.scroll(0,0);
$("body,html,document").scrollTop(0);
$("body,html").scrollTop(0);

Which I suppose extends my question, is this a css issue? I dont have an outside link and the code is too long (made with CI view Partials) to post all of it, but to CLARIFY what i've done:

• Fixed header, footer, and sidebar leaving content to scroll with documet scrollbar
• very little javascript or jquery implemented thus far, almost 0 custom css outside of fixing position of presaid elements
• the "content" is ajax'd in using jQuery's .load function based on list items clicked in sidebar navigator

temp Fiddle no longer up

回答1:

The problem is with CSS. In particular, the rules I've included below.

html, body {
    overflow-x: hidden;
    overflow-y: auto;
}

Though these rules are obviously related to scrollbars, I'm not sure why they are causing the behavior you are observing. But if you remove them, it should solve your problem.

See: http://jsfiddle.net/jNWUm/23/.

回答2:

I had the same problem. If I put

$(window).scrollTop(0);

in the document ready handler, it didn't work; but if I test it in the javascript console panel of Chrome developer toolkit, it worked! The only difference was the execution time of the script. So I tried

window.setTimeout(function() {
    $(window).scrollTop(0); 
}, 0);

and it worked. Setting a delay greater than 0 is not neccesary, although that also worked. It's not jQuery's fault, because it is the same with

window.scrollTo(0, 0);  window.scroll(0, 0);

So the reason might be the browser populates the window.pageYOffset property after it renders the page and executes the js.

回答3:

For people that need the overflow settings, the workaround is to use an animation like this.

    $('#element_id').stop().animate({ scrollTop: 0 }, 500);

This seems to behave better than .scrollTop(0).

回答4:

I just tested the following in IE8 and Chrome and both work:

$(window).scrollTop(0)

回答5:

Also check out this answer: scrolltop broken on android - it seems to work best when overflow is set to visible and position to relative - but ymmv. You might find these useful...

function repeatMeOnMouseDown() // for smooth scrolling
{
    var $newTop = $('#element_id').position().top + ($goingUp ? -20 : 20);
    $('#element_id').animate({top: $newTop}, 20, repeatMeOnMouseDown); 
}

// these should work
$('#element_id').animate({top: -200}, 200); // scroll down
$('#element_id').animate({top: 0}, 200); // scroll back up

// DON'T DO THIS - Offsets don't work with top like they do with scrollTop 
$('#element_id').animate({top: ("-= " + 200)}, 200);

// and when you get tired of fighting to do smooth animation 
// on different browsers (some buggy!), just use css and move on
function singleClick($goingUp)
{
   var $newTop = $('#element_id').position().top + ($goingUp ? -200 : 200);
    $('#element_id').css({top: $newTop}, 20); 
}

回答6:

FYI, if not in top body, i.e. in an iframe, just try window.top.scrollTo(0,0);

回答7:

I had a same problem with scrolling in chrome. Reason was height:100% style in body and html. See this answer

回答8:

This code was tested in chrome. http://jsfiddle.net/wmo3o5m8/1/

(function () {
    var down = false, downX, downY;
    document.onmousedown = function (e) {
        downX = e.pageX;
        downY = e.pageY;
        down = true;
    };
    document.onmouseup = function () { down = false; };
    document.onmousemove = function (e) {
        if (down) {
            window.scrollTo(
                window.scrollX + downX - e.pageX,
                window.scrollY + downY - e.pageY
            );
        }
    };
})();

回答9:

This is the normal behaviour when in your css you are declaring overflow: hidden for html or body dom elements, as you can read in the jQuery API docs:

The vertical scroll position is the same as the number of pixels that are hidden from view above the scrollable area. If the scroll bar is at the very top, or if the element is not scrollable, this number will be 0.

With overflow: hidden the scroll bar is not visible hence element not scrollable, so the number will be 0 in every (I wonder) browser you will use.

回答10:

$('#element-id').prop('scrollTop', 0); should also do the trick.