平滑滚动，可播放多个不同高度的固定导航栏

Question

I have a fixed-top navbar (75px height) with smooth scroll working perfectly well for desktop. When I'm on small screen I have a different navbar (50px height) with less height so the anchor dosent arrive a the right place.

// Smooth Scoll
$('a[href*="#"]')
    .not('[href="#"]')
    .not('[href="#0"]')
.click(function(event) {
       if (
        location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//,'')
        &&
            location.hostname == this.hostname
       ) {
           var target = $(this.hash);
           target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
           if (target.length) {
               event.preventDefault();
               $('html, body').animate({
                   scrollTop: target.offset().top -75
               }, 1200, function() {
                   var $target = $(target);
                   $target.focus();
                   if ($target.is(":focus")) {
                       return false;
                   } else {
                       $target.attr('tabindex','-1');
                       $target.focus();
                   };
               });
           }
       }
});

I want to be able to set the target.offset().top depending on the navbar that is clicked. No css solutions please.

Answer 1

Add a screen width check and change the 75 to 50

// Smooth Scoll
$('a[href*="#"]').not('[href="#"]') .not('[href="#0"]').click(function(event) {
       if (location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//,'') && location.hostname == this.hostname) {
           var target = $(this.hash);
           target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
           if (target.length) {
               event.preventDefault();
               $('html, body').animate({

                // change dependant on screen width
                if ($(window).width() < 960) { // set in px
                    scrollTop: target.offset().top -50
                } else {
                   scrollTop: target.offset().top -75
                }          

               }, 1200, function() {
                   var $target = $(target);
                   $target.focus();
                   if ($target.is(":focus")) {
                       return false;
                   } else {
                       $target.attr('tabindex','-1');
                       $target.focus();
                   };
               });
           }
       }
});

Or you could, which might be better get the nav height on click

//set nav 
var nav = $('.nav-bar'); // update to your nav class

// Smooth Scoll
$('a[href*="#"]').not('[href="#"]').not('[href="#0"]').click(function(event) {

    // get nav height
    var NavHeight = nav.height();

       if (location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//,'') && location.hostname == this.hostname ) {
           var target = $(this.hash);
           target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
           if (target.length) {
               event.preventDefault();
               $('html, body').animate({

                // minus nav height
                scrollTop: target.offset().top - NavHeight

               }, 1200, function() {
                   var $target = $(target);
                   $target.focus();
                   if ($target.is(":focus")) {
                       return false;
                   } else {
                       $target.attr('tabindex','-1');
                       $target.focus();
                   };
               });
           }
       }
});