圖片不會隱藏在滾動jQuery

Question

你好，我正在一個項目上，我發現一個免費的小提琴使用codepen.io。在網站上，它完美的工作，當你去我爲它製作的js小提琴時，有一個問題。當您向下滾動至主要內容時，主標題和框會顯示在文字上方。有沒有一種方法可以消除這種情況發生在原來的codepen上？

小提琴HERE

function EasyPeasyParallax() { 
 
\t scrollPos = $(this).scrollTop(); 
 
\t $('#banner').css({ 
 
\t \t 'background-position' : '50% ' + (-scrollPos/4)+"px" 
 
\t }); 
 
\t $('#bannertext').css({ 
 
\t \t 'margin-top': (scrollPos/4)+"px", 
 
\t \t 'opacity': 1-(scrollPos/250) 
 
\t }); 
 
} 
 
$(document).ready(function(){ 
 
\t $(window).scroll(function() { 
 
\t \t EasyPeasyParallax(); 
 
\t }); 
 
});

Answer 1

添加

background: #fff; 
    position: relative; 

到＃內容元素。

實施例：https://jsfiddle.net/gu7dt5oz/1/

Answer 2

如果正確地記得z索引僅適用於定位的元素。

我加了「position：relative;」 #content，#content p和#banner，它似乎工作。

html { 
    height: 100%; 
} 

body { 
    background: #FFF; 
    font: 400 1.5em/1.5 "Droid Serif", serif; 
    color: #111; 
    text-align: center; 
    height: 100%; 
} 

h1 { 
    font: 700 2.8em/1.2 "Droid Sans", sans-serif; 
} 

h2 { 
    font: 700 1.5em/1.5 "Droid Sans", sans-serif; 
    margin: 1em 0; 
} 

#banner { 
    background: url(http://f.cl.ly/items/1b2V08451N440W0H420K/bg.jpg) no-repeat fixed 50% 0; 
    background-size: cover; 
    color: #fff; 
    height: 100%; 
    margin-left: -7px; 
    margin-top: -8px; 
    width: 100%; 
    z-index: 1; 
    position:relative; 
} 

#bannertext { 
    width: 24em; 
    position: fixed; 
    top: 20%; 
    left: 50%; 
    border: .5em solid #fff; 
    margin-left: -12em; 
    padding: 2em 0; 
    z-index: 1; 
} 

#content { 
    max-width: 28em; 
    text-align: justify; 
    margin: 0 auto; 
    padding: 2em; 
    z-index: 10; 
    position:relative; 
} 

#content p { 
    margin: 0 0 2em; 
    z-index: 10; 
    position:relative; 
} 

Answer 3

編織：http://kodeweave.sourceforge.net/editor/#dcbf9c586b0e798fce89be31c50e3950

注：zIndex僅適用於positioned元素。

我所做的只是告訴#content爲position relative，它工作正常。

html, body { 
 
    height: 100%; 
 
} 
 

 
body { 
 
    background: #FFF; 
 
    font: 400 1.5em/1.5 "Droid Serif", serif; 
 
    color: #111; 
 
    text-align: center; 
 
} 
 

 
h1 { 
 
    font: 700 2.8em/1.2 "Droid Sans", sans-serif; 
 
} 
 
h2 { 
 
    font: 700 1.5em/1.5 "Droid Sans", sans-serif; 
 
    margin: 1em 0; 
 
} 
 

 
#banner { 
 
    background: url(http://f.cl.ly/items/1b2V08451N440W0H420K/bg.jpg) no-repeat fixed 50% 0; 
 
    background-size: cover; 
 
    color: #fff; 
 
    height: 100%; 
 
    margin-left: -7px; 
 
    margin-top: -8px; 
 
    width: 100%; 
 
    z-index: 1; 
 
} 
 
#bannertext { 
 
    width: 24em; 
 
    position: fixed; 
 
    top: 20%; 
 
    left: 50%; 
 
    border: .5em solid #fff; 
 
    margin-left: -12em; 
 
    padding: 2em 0; 
 
    z-index: 1; 
 
} 
 

 
#content { 
 
    position: relative; 
 
    max-width: 28em; 
 
    text-align: justify; 
 
    margin: 0 auto; 
 
    padding: 2em; 
 
    z-index: 10; 
 
} 
 
#content p { 
 
    margin: 0 0 2em; 
 
    z-index: 10; 
 
}

<div id="banner"> 
 
    <div id="bannertext"> 
 
    <h1>| EX |</h1> 
 
    <p>Get famous on twitter.</p> 
 
    </div> 
 
</div> 
 

 
<div id="content"> 
 
    <h2>EX</h2> 
 
    <br> 
 
    <br> 
 
    <br> 
 
    <h2>EX.</h2> 
 
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Proin pellentesque, est ut venenatis aliquam, lorem quam porttitor ligula, eget ultrices velit dui sed quam. Praesent vehicula placerat lectus. Nulla pede. Quisque a nulla quis massa pulvinar sagittis. Pellentesque neque massa, mattis vulputate, pellentesque nec, vehicula volutpat, purus. Proin pretium dui et nulla cursus eleifend. Aenean aliquam urna eget urna. Vestibulum euismod elit. Donec eget augue sit amet neque elementum pretium. Proin posuere lacus id lacus. Duis vel justo suscipit neque ornare iaculis.</p> 
 
    <p>Ut urna urna, rhoncus eget, vestibulum tempus, venenatis non, nunc. Nunc consequat quam in nulla. Praesent feugiat posuere orci. Sed ac ante. Mauris pellentesque massa vitae ante mattis bibendum. Quisque dapibus lectus eu eros. Nulla facilisi. Praesent hendrerit egestas erat. Suspendisse at velit. Quisque mollis feugiat est. Curabitur ut leo. Cras auctor semper augue. Pellentesque leo pede, tempus sed, ornare in, venenatis sed, nisl. Quisque est velit, eleifend vitae, mollis ac, adipiscing at, eros. Mauris velit. Etiam nec lorem. Vestibulum pellentesque ligula a velit. Maecenas felis metus, suscipit et, eleifend vel, accumsan vitae, magna. Phasellus ut justo vel magna congue laoreet.</p> 
 
</div>

Answer 4

只需使用最新版本的jQuery，它工作正常

小提琴：https://jsfiddle.net/gu7dt5oz/2/

<script src="https://code.jquery.com/jquery-2.2.3.min.js" 
integrity="sha256-a23g1Nt4dtEYOj7bR+vTu7+T8VP13humZFBJNIYoEJo=" 
crossorigin="anonymous"></script>