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How to hide/show nav bar when user scrolls up/down

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面向向阳花
面向向阳花 2020-12-12 18:49

Hide/show nav bar when user scrolls up/down

Here\'s the example I\'m trying to achieve: http://haraldurthorleifsson.com/ or http://www.teehanlax.com

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6条回答
  • 时光说笑
    2020-12-12 18:59

    I found a similar and simpler implementation of @Dom Day written about by Saijo George.

    NOTE: I renamed Saijo's variables so it would be easier for me to read.

    CSS

    /* This class will be attached to your nav by the below */
.scrollUp {
  transform: translateY(-100%);
}

    jQuery

    const navbar = document.querySelector("nav"); //Select your nav element here
let previousScroll = 0;

$(window).scroll(function handleNav() {
  let currentScroll = $(window).scrollTop(); //Distance scrolled down the page
  let navHeight = $(navbar).height(); //Height of navbar

  //When scrolling down AND you've scrolled past navHeight * 2.25, add .scrollUp
  if (currentScroll > previousScroll && currentScroll > navHeight * 2.25) {
    $(navbar).addClass("scrollUp");
    //When scrolling up AND you've scrolled less than navHeight, remove .scrollUp
  } else if (previousScroll > currentScroll && !(currentScroll <= navHeight)) {
    $(navbar).removeClass("scrollUp");
  }
  previousScroll = currentScroll;
});
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  • 庸人自扰
    2020-12-12 19:00

    css

    @media(min-width: 1079px){
    #header{
        width:100%;
        height:82px;
        border:1px solid grey;
        background-color: lightgreen;
        margin:0 auto;
        position:fixed;
        transition-property: all;
        transition-duration: 0.3s;
        transition-delay: 0s;
        transition-timing-function: ease-out;
    }
    nav{
        display: flex;
        justify-content: space-between;
    }
    nav .nav1{
        list-style-type: none;
        padding: 0px;
    }
    nav a{
        text-decoration: none;
        color:grey;
        padding: 13px;
        display: block;
        color: grey;
        margin-top: 15px;
    }
    a{
        text-decoration: none !important;
    }
    nav a:hover{
        color: red;
    }
    nav .nav1{
        display: flex;
        justify-content: flex-end;
    }
    .row2{
        background-color: skyblue;
        height:2000px;
        margin-top: 82px;
    }
}

    html

    <!DOCTYPE html>
<html>
<head>

    <title>header2</title>
    <link rel="stylesheet" type="text/css" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    <meta name="viewport" content="width=device-width, initial-scale=1">
   <script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
    <link rel="stylesheet"  href="css/header-larger1.css">
</head>
<body>
    <!--<div id="header">-->
        <nav>
            <ul class="nav1" id="header">
                <li><a href="">HOME</a></li>
                <li><a href="">ABOUT</a></li>
                <li><a href="">INFO</a></li>
                <li><a href="">DISCOUNTS</a></li>
                <li><a href="">BUSINESS</a></li>
                <li><a href="">BLOG</a></li>
                <li><a href="">CONTACT</a></li>
            </ul>
        </nav>
    <!--</div>-->
    <div class="container row2">
        <h3>this is row2</h3>
    </div>
</body>
<script src="http://code.jquery.com/jquery-1.11.3.min.js"></script>
<script type="text/javascript" src="js/head1.js"></script>
</html>

    js

    function fun1()
{
     var documentElem=$(document),

     lastScrollTop=0;
     scrollabc=80;

     documentElem.on('scroll',function()
     {
        var currentScrollTop=$(this).scrollTop();
        console.log(window.pageYOffset);
        if(currentScrollTop > scrollabc)
        {
            if(currentScrollTop>lastScrollTop)
            {
           //nav.addClass('hidden'); 
            document.getElementById("header").style.marginTop = "-80px";
            console.log("first if block");
            }
        else
        {
          // nav.removeClass('hidden'); 
           document.getElementById("header").style.marginTop = "0px";
           console.log("2nd if block");
        } 
    }
        lastScrollTop=currentScrollTop;
    })
}



fun1();
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  • 暗喜
    2020-12-12 19:03

    Whatever navbar element you use, it has to include a transition: transform 0.3s on it, and a base transform of 0.

    #navbar {
    position: fixed;
    right: 0; left: 0; top: 0; 
    /* your height */
    height: 40px;
    /* .... */
    -webkit-transform: translate3d(0,0,0);
    -moz-transform: translate3d(0,0,0);
    transform: translate3d(0,0,0);
    -webkit-transition: -webkit-transform .3s;
    -moz-transition: -moz-transform .3s;
    -o-transition: transform .3s;
    transition: transform .3s;
}
#navbar.scrolled {
    /* subtract your height */
    -webkit-transform: translate3d(0,-40px,0);
    -moz-transform: translate3d(0,-40px,0);
    transform: translate3d(0,-40px,0);
}

    Then your javascript needs to watch the user's scrolling:

    ;(function (){
    var previousScroll = 0;
    var navbar = document.getElementById('navbar'),
        navClasses = navbar.classList; // classList doesn't work <IE10

    window.addEventListener('scroll', function(e){
       var currentScroll = window.scrollY;
       var isDown = currentScroll > previousScroll;

       if ( isDown && !navClasses.contains('scrolled') ){
          // scrolling down, didn't add class yet
          navClasses.add('scrolled'); // we hide the navbar
       } else if ( !isDown ){
          // scrolling up
          navClasses.remove('scrolled'); // won't error if no class found
       }

       // always update position
       previousScroll = currentScroll;
    });
}()); //run this anonymous function immediately
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  • 离开以前
    2020-12-12 19:05

    Have you tried animate? but replace the -60px with the height of the navbar. But negative.

    $(window).scroll(function() {
    var currentScroll = $(this).scrollTop();
    console.log(currentScroll + " and " + previousScroll + " and " + headerOrgOffset);
    if(currentScroll > headerOrgOffset) {
        if (currentScroll > previousScroll) {
            $('#header').animate({
                 top: '-60px'      //Change to Height of navbar
            }, 250);               //Mess with animate time
        } else {
            $('#header').animate({
                 top: '0px'
            },250);
            $('#header').addClass('fixed');
        }
    } else {
         $('#header').removeClass('fixed');   
    }
    previousScroll = currentScroll;
});
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  • 温柔的废话
    2020-12-12 19:09

    To get the inner content of the nav to slide up instead of being progressively hidden, you need to do the animation on the parent element, and keep the inner element at the bottom of the parent, like so:

    jsfiddle

    <div id="header-wrap">
    <div id="header" class="clear">
        <nav><h1>Prototype</h1>another line<br/>another line
        </nav>
    </div>
</div>

    css

    body {
    height: 1000px;
}

#header {
    width: 100%;
    position: absolute;
    bottom: 0;
}

#header-wrap {
    width: 100%;
    position: fixed;
    background-color: #e0e0e0;
}

    js

    var previousScroll = 0,
    headerOrgOffset = $('#header').height();

$('#header-wrap').height($('#header').height());

$(window).scroll(function () {
    var currentScroll = $(this).scrollTop();
    if (currentScroll > headerOrgOffset) {
        if (currentScroll > previousScroll) {
            $('#header-wrap').slideUp();
        } else {
            $('#header-wrap').slideDown();
        }
    } else {
            $('#header-wrap').slideDown();
    }
    previousScroll = currentScroll;
});
    0 讨论(0)
  • 执笔经年
    2020-12-12 19:15

    Try headroom js.

    Also you can edit the CSS classes and deploy the transition effect.

    http://wicky.nillia.ms/headroom.js

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