jQuery平滑滚动到顶部并按ID锚定（带有偏移）

Question

this is an extension to a questions that was previously answered here: See Prevoius Question

I have a bit of jQuery that is adding BOTH a smooth scroll to top function, AND a smooth scroll to any anchor found on a page.

Now, I just need to add an offset to the anchor scroll (110px) to account for fixed headers, WITHOUT messing up the scroll to top function.

Here's the existing code:

// Add To Top Button + Smooth Scroll to Anchors functionality
jQuery(document).ready(function($){
    // Scroll (in pixels) after which the "To Top" link is shown
    var offset = 700,
    //Scroll (in pixels) after which the "back to top" link opacity is reduced
    offset_opacity = 1200,
    //Duration of the top scrolling animation (in ms)
    scroll_top_duration = 700,
    //Get the "To Top" link
    $back_to_top = $('.to-top');

//Visible or not "To Top" link
$(window).scroll(function(){
    ( $(this).scrollTop() > offset ) ? $back_to_top.addClass('top-is-visible') : $back_to_top.removeClass('top-is-visible top-fade-out');
    if( $(this).scrollTop() > offset_opacity ) { 
        $back_to_top.addClass('top-fade-out');
    }
});

//Smooth scroll to top
$back_to_top.on('click', function(event) {
    event.preventDefault();
    targetedScroll();
});

// example of smooth scroll to h2#anchor-name
$('#some-button').on('click', function(event) {
    event.preventDefault();
    targetedScroll('anchor-name');
});

// bind smooth scroll to any anchor on the page
$('a[href^="#"]').on('click', function(event) {
    event.preventDefault();
    targetedScroll($(this).attr('href').substr(1));
});

// scrolling function
function targetedScroll(id) {
    // scrollTop is either the top offset of the element whose id is passed, or 0
    var scrollTop = id ? $('#' + id).offset().top : 0;

    $('body,html').animate({
        scrollTop: scrollTop,
    }, scroll_top_duration);
}

});

Answer 1

Any time your're scrolling to an element, you have to scroll lower than the element by the height of the fixed navbar. Similarly, the first element on the page needs a margin or padding to offset by the height of the navbar.

Since both of these offsets are the same, you can set the offset for scrolling at the same time you set the offset for the first element. When you're scrolling to an element, subtract the offset from the height from the top. This will still work even when scrolling to the top.

jQuery(document).ready(function($) {
    var offset = $("nav").height();
    $("body").css("padding-top", offset + "px");
    $('a[href^="#"]').click(function(event) {
        event.preventDefault();
        var scrollY = $(this.href).offset().top;
        $('html, body').animate({
            scrollTop: scrollY - offset
        }, 2000);
    });
});