Jquery: scroll page down 100px from where it curre

问题:

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• ;Jquery: animate page down 100px from current screen position 3 answers

How do I animate the page down 100px from where it currently is?

my code doesn't work:

    $('html,body').animate({
        scrollTop: $(window).position().top + 100
    })

like this, but without it scrolling the page to a specific element, instead, scrolling 100px from the windows current position:

$('html, body').animate({
scrollTop: $("#scrollToHere").offset().top
}, 2000);

回答1:

The scrollto plugin comes to mind:
http://flesler.blogspot.com/2007/10/jqueryscrollto.html
http://demos.flesler.com/jquery/scrollTo/

but maybe it's a bit overkill for that :)

回答2:

The scrollTop property tells you where the element is placed from the top. You have to use the window.scrollBy method and the window.scrollY property. Unfortunately you can't use animate on the window.scrollY property since it's read-only.

You should be able to use something like this:

function animateScrollBy (x, y, interval) {
    var xpos = 0,
    ypos = 0,
    updateScroll = function () {
        var moveX = xpos <= x ? 1 : 0,
            moveY = ypos <= y ? 1 : 0;

        window.scrollBy(moveX, moveY);
        xpos += 1;
        ypos += 1;
        if (moveX === 0 && moveY === 0) {
            clearInterval(scrollInterval);
        }

    },
    scrollInterval = null;

    scrollInterval = setInterval(updateScroll, interval||1)
}

animateScrollBy(0, 100);

The speed is relavant to the amout of pixels moved. I'll try it to update it later.