Use a DIV as a background for another element

问题

If I have a div that contains images and text, is it possible to use this div's content as a background for, let's say, a section ?

For example, something like that :

HTML:

<section id="sec1">
    <div id="bg-div">
        <em>This is a background</em>
        <img src="image1">
        <img src="image2">
    </div>
</section>

And CSS:

#sec1 {
    background: src(#bg-div);
}

This way, I could have this div content acting like a background for my section.

回答1:

Here I made an example with 2 divs:

.content which contains everything you need in frontend
.background - with text, images and everything else in background

To overwrap one div on another (make an overlay) you have to put them into same element, in this example it's #wrapper div. Put position: relative and width/height for wrapper; position: relative also should be set for your content div and position: absolute; top: 0; left: 0; for your background.

The final step is to setup z-index. Element containing a bigger value in z-index is rendered above elements with smaller z-index value. In other words you should set z-index for background div smaller then for content div.

Final HTML:

<div id="wrapper">
    <div class="content">    
        <p>This text is in frontend</p>
    </div>
    <div class="background">
        <p>Background text</p>
        <img src="http://nuclearpixel.com/content/icons/2010-02-09_stellar_icons_from_space_from_2005/earth_128.png" alt="background" />
        <img src="http://upload.wikimedia.org/wikipedia/en/0/0c/IrfanView_Logo.png" alt="background 2" />

    </div>
</div>

Final CSS:

#wrapper{
    position: relative;
    width: 200px;
    height: 200px;
}

.content{
    color: #FFFFFF;
    font-size: 26px;
    font-weight: bold;
    text-shadow: -1px -1px 1px #000, 1px 1px 1px #000;
    position: relative;
    z-index: 100;
}

.background{
    color: #999999;
    position: absolute;
    top: 0;
    left: 0;
    z-index: -100;
}

View live example:

http://jsfiddle.net/1fevoyze/

回答2:

Use the CSS element() function. See https://developer.mozilla.org/en-US/docs/Web/CSS/element. Currently available only in FF under the -moz-element prefix. Example:

<div style="width:400px; height:100px; background:-moz-element(#backgroundElt);">

An alternative would be to play with SVG's foreignObject tag, cloning the HTML for the element you want to use as background into it.

Spec is at http://dev.w3.org/csswg/css-images/#element-notation.

来源：https://stackoverflow.com/questions/25970787/use-a-div-as-a-background-for-another-element

标签

html

css

background

background-image