固定的 CSS 位置不会出现在移动设备上

Question

我有一个类似这个 css 的元素:

element.style {
    background-image: url(image.jpg);
}
.panel-image {
    background-position: center center;
    background-repeat: no-repeat;
    -webkit-background-size: cover;
    background-size: cover;
    position: relative;
}

我现在正试图让它成为一个固定位置，所以当我尝试执行以下操作时:

.panel-image {
    background-position: center center;
    background-repeat: no-repeat;
    -webkit-background-size: cover;
    background-size: cover;
    position: fixed;
    width: 100%;
    height: 200px;
}

该元素不再出现在页面上。

有一个元素环绕着这个元素:

.twentyseventeen-panel {
    overflow: hidden;
    position: relative;
}

这是 html:

<article id="panel1" class="twentyseventeen-panel  post-47 page type-page status-publish has-post-thumbnail hentry">


        <div class="panel-image" style="background-image: url(https://2017.wordpress.net/wp-content/uploads/2016/10/pexels-photo-30724-2000x1200.jpg);">
            <div class="panel-image-prop" style="padding-top: 60%"></div>
        </div><!-- .panel-image -->


    <div class="panel-content">
        <div class="wrap">
            <header class="entry-header">
                <h2 class="entry-title">Our Drinks</h2>

            </header><!-- .entry-header -->

            <div class="entry-content">
                <h2>Coffee and Espresso</h2>
<p><strong>Drip Coffee</strong>&nbsp;$2.50</p>
<p><strong>Espresso Shots</strong> $3.00</p>
<p><strong>Americano</strong>&nbsp;$4.50</p>
<p><strong>Cappuccino</strong>&nbsp;$4.50</p>
<p><strong>Macchiato</strong>&nbsp;$4.50</p>
<p><strong>Cortado</strong>&nbsp;$4.50</p>
<p><strong>Flat White</strong>&nbsp;$5.00</p>
<p><strong>Latte</strong>&nbsp;$4.50<br>
<em>hot or iced</em></p>
<p><strong>Mocha</strong>&nbsp;$4.50<br>
<em>hot or iced</em></p>
<p><strong>Cold Brew</strong> $4.00<br>
<em>regular or nitro</em></p>
<h2>Other Drinks</h2>
<p><strong>Chai</strong><strong>&nbsp; </strong>$4.50</p>
<p><strong>Iced Tea&nbsp;&nbsp;</strong>$3.50<br>
<em>green, black, or white</em></p>
<p><strong>Hot Tea</strong><strong>&nbsp;&nbsp;</strong>$3.00<br>
<em>english breakfast, ceylon, green, white, chamomile, rooibos, peach</em></p>
<p><strong>Flavored Sodas</strong><strong>&nbsp; </strong>$4.00<br>
<em>raspberry, blueberry, peach, mango, vanilla, mint</em></p>
            </div><!-- .entry-content -->


        </div><!-- .wrap -->
    </div><!-- .panel-content -->

</article>

我的问题是，如何让带有背景图片的元素固定。

这是一个示例站点:

http://www.grogenex.com/

Answer 1

这是另一种方法，它不使用“background-attachment”或“position: fixed”。

.panel-image {
    background-position: center center;
    background-repeat: no-repeat;
    -webkit-background-size: cover;
    background-size: cover;
    position: relative;
    z-index: 0;
    width: 100%;
    height: 100%;
}
.twentyseventeen-panel {
    overflow: hidden;
    position: relative;
    height: 400px;
}
.panel-content {
  position: absolute;
  top: 0 !important;
  left: 0 !important;
  overflow: auto !important;
  height: 100%;
  width: 100%;
  z-index: 1;
}
.panel-content > .wrap {
    position: relative;
    background: rgba(255,255,255,0.8);
    top: 200px;
}

<article id="panel1" class="twentyseventeen-panel  post-47 page type-page status-publish has-post-thumbnail hentry">


        <div class="panel-image" style="background-image: url(https://2017.wordpress.net/wp-content/uploads/2016/10/pexels-photo-30724-2000x1200.jpg);">
            <div class="panel-image-prop" style="padding-top: 60%"></div>
        </div><!-- .panel-image -->


    <div class="panel-content">
        <div class="wrap">
            <header class="entry-header">
                <h2 class="entry-title">Our Drinks</h2>

            </header><!-- .entry-header -->

            <div class="entry-content">
                <h2>Coffee and Espresso</h2>
<p><strong>Drip Coffee</strong>&nbsp;$2.50</p>
<p><strong>Espresso Shots</strong> $3.00</p>
<p><strong>Americano</strong>&nbsp;$4.50</p>
<p><strong>Cappuccino</strong>&nbsp;$4.50</p>
<p><strong>Macchiato</strong>&nbsp;$4.50</p>
<p><strong>Cortado</strong>&nbsp;$4.50</p>
<p><strong>Flat White</strong>&nbsp;$5.00</p>
<p><strong>Latte</strong>&nbsp;$4.50<br>
<em>hot or iced</em></p>
<p><strong>Mocha</strong>&nbsp;$4.50<br>
<em>hot or iced</em></p>
<p><strong>Cold Brew</strong> $4.00<br>
<em>regular or nitro</em></p>
<h2>Other Drinks</h2>
<p><strong>Chai</strong><strong>&nbsp; </strong>$4.50</p>
<p><strong>Iced Tea&nbsp;&nbsp;</strong>$3.50<br>
<em>green, black, or white</em></p>
<p><strong>Hot Tea</strong><strong>&nbsp;&nbsp;</strong>$3.00<br>
<em>english breakfast, ceylon, green, white, chamomile, rooibos, peach</em></p>
<p><strong>Flavored Sodas</strong><strong>&nbsp; </strong>$4.00<br>
<em>raspberry, blueberry, peach, mango, vanilla, mint</em></p>
            </div><!-- .entry-content -->


        </div><!-- .wrap -->
    </div><!-- .panel-content -->

</article>