代码之家 › 专栏 › 技术社区 › Haox

如何不透明的背景标题与滚动

css html jquery javascript

Haox · 技术社区 · 6 年前

我期待着不透明的背景颜色,我的导航栏在滚动。

事实上,当我滚动我的导航栏是混合的内容,我不能阅读任何东西。

我试过很多教程,但是我的javascript知识很差,什么都不管用。

我只想背景标题是不透明0时,我们在页面的顶部,并成为0.7时,我们滚动。

/*sticky_navbar*/

window.onscroll = function() {
  myFunction()
};

var navbar = document.getElementById("header");
var sticky = navbar.offsetTop;

function myFunction() {
  if (window.pageYOffset >= sticky) {
    navbar.classList.add("sticky")
  } else {
    navbar.classList.remove("sticky");
  }
}


$(window).scroll(function() {
  var threshold = 200; // number of pixels before bottom of page that you want to start fading
  var op = (($(document).height() - $(window).height()) - $(window).scrollTop()) / threshold;
  if (op <= 0) {
    $("#header").hide();
  } else {
    $("#header").show();
  }
  $("#header").css("opacity", op);
});

#header {
  display: flex;
  justify-content: flex-end;
  background: rgba(139, 139, 157, 0.7);
  z-index: 2;
}

.navbar {}

#Title {
  margin: 0 auto 0 0;
  height: 20px;
  margin-top: 15px;
  padding-left: 10px;
  border-bottom: 1px solid white;
  padding-top: 5px;
  padding-bottom: 30px;
  flex: 1;
}

#navbar {
  overflow: hidden;
  display: flex;
  justify-content: flex-end;
  border-bottom: 5px solid white;
  padding-bottom: 10px;
  padding-top: 15px;
}

.menu:nth-child(1) {
  order: 1;
}

.menu:nth-child(2) {
  order: 4;
}

.menu:nth-child(3) {
  order: 3;
}

.menu:nth-child(4) {
  order: 2;
}

.menu:nth-child(5) {
  order: 5;
}

IMG.background {
  display: block;
  margin-left: auto;
  margin-right: auto;
  z-index: 1;
  width: 60%;
}

#navbar a {
  display: block;
  color: #FFF;
  text-align: center;
  padding: 10px 16px;
  text-decoration: none;
  font-size: 17px;
}

#navbar a:hover {
  background-color: #ddd;
  color: black;
}

#navbar a.active {
  background: rgba(217, 78, 68, 0.5);
  color: white;
}

.content {
  padding: 16px;
  color: #ddd;
  background-color: #FFF
}

.sticky {
  position: fixed;
  top: 0;
  width: 100%;
}

.sticky+.content {
  padding-top: 60px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="header" class="navbar">
  <div id="Title">
    <a href="Accueil"><img src="IMAGES/PNG/logo.png" alt="logo" /></a>
  </div>
  <div id="navbar">
    <div class="menu"> <a class="active" href="javascript:void(0)">Blog</a></div>
    <div class="menu"> <a href="blog">Contact</a></div>
    <div class="menu"> <a href="blog">L'Ã©lectrophotonique</a></div>
    <div class="menu"> <a href="blog">Qui sommes nous?</a></div>
  </div>
</div>

2 回复 | 直到 6 年前

Mandalina 6 年前

我还添加了一个css转换,使其淡出,但这只是个人喜好的问题。如果你愿意的话,你可以把它去掉。

CODEPEN

css格式

   #header {
      display: flex;
      justify-content: flex-end;
      background: rgba(139, 139, 157, 0);
        -webkit-transition: background 0.5s ease-in-out;
      -moz-transition: background 0.5s ease-in-out;
      -ms-transition: background 0.5s ease-in-out;
      -o-transition: background 0.5s ease-in-out;
      transition: background 0.5s ease-in-out;
      z-index: 2;
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
    }

#header.isSticky {
  background: rgb(139, 139, 157, 0.7);
    -webkit-transition: background 0.5s ease-in-out;
  -moz-transition: background 0.5s ease-in-out;
  -ms-transition: background 0.5s ease-in-out;
  -o-transition: background 0.5s ease-in-out;
  transition: background 0.5s ease-in-out;
}

js公司

$(document).ready(function(){// checks vertical position of scroll bar 
var scrollY = $(this).scrollTop();
// when user refreshes psge
if (scrollY > 0) {
  // if it is anywhere but the top change opacity by adding class .isSticky
  $('#header').addClass('isSticky');
} else {
  $('#header').removeClass('isSticky');
}


$(window).on('scroll', function(){
  // while uesr scrolls check the scrollTop position
  var scrollY = $(this).scrollTop();
  if (scrollY > 0) {
   $('#header').addClass('isSticky');
  } else {
   $('#header').removeClass('isSticky');
  }
});
});

Mattia Astorino 6 年前

.isSticky 例如)通过选中元素offset top来滚动js。

#header {
  display: flex;
  justify-content: flex-end;
  background: rgba(139, 139, 157, 0);
  z-index: 2;
}

#header.isSticky {
  background: rgba(139, 139, 157, 0.7);
}