css3 content attribute-CSS Tutorial-php.cn

css3 content attribute

伊谢尔伦

Release： 2017-02-03 14:08:38

Original

1851 people have browsed it

There are four main pseudo-elements in CSS: before/after/first-letter/first-line. In the before/after pseudo-element selector, there is a content attribute that can insert content into the page.

Insert plain text

content: "Inserted article", or content:none does not insert content

#html
<h1>这是h1</h1>
<h2>这是h2</h2>
#css
h1::after{
    content:"h1后插入内容"
}
h2::after{
    content:none
}

Copy after login

Embedded text symbols

You can use the content attribute The open-quote attribute value and the close-quote attribute value add nested literal symbols such as brackets, single quotes, and double quotes on both sides of the string. open-quote is used to add the starting text symbol, and close-quote is used to add the ending text symbol. Modify the above css:

h1{
    quotes:"(" ")";  /*利用元素的quotes属性指定文字符号*/
}
h1::before{
    content:open-quote;
}
h1::after{
    content:close-quote;
}
h2{
    quotes:"\"" "\"";  /*添加双引号要转义*/
}
h2::before{
    content:open-quote;
}
h2::after{
    content:close-quote;
}

Copy after login

Insert picture

content attribute can also insert pictures directly before/after the element

#html
<h3>这是h3</h3>

#css
h3::after{
    content:url(图片路径)
}

Copy after login

Insert attribute value of element

The content attribute can directly use attr to obtain the attributes of the element and insert it into the corresponding position.

#html
<a href="http://www.php.cn">这是链接</a>

#css
a:after{
    content:attr(href);
}

Copy after login

Insert item number

Use the counter attribute of content to append consecutive numbers to multiple items.

#html
<h1>大标题</h1>
<p>文字</p>
<h1>大标题</h1>
<p>文字</p>
<h1>大标题</h1>
<p>文字</p>
<h1>大标题</h1>
<p>文字</p>

#css
h1:before{
    content:counter(my)&#39;.&#39;;
}
h1{
    counter-increment:my;
}

Copy after login

Item number modification

The default inserted item number It is numerical, 1,2,3. . . Automatic increment, you can also add text and styles to the project number. Still use the above html, css modification as follows:

h1:before{
    content:&#39;第&#39;counter(my)&#39;章&#39;;
    color:red;
    font-size:42px;
}
h1{
    counter-increment:my;
}

Copy after login

Specify number type

Use content (counter name, number type) format The syntax specifies the numbering type. The reference to the numbering type can be based on the list-style-type attribute value of ul. Using the above html, the css is modified as follows:

h1:before{
    content:counter(my,upper-alpha);
    color:red;
    font-size:42px;
}
h1{
    counter-increment:my;
}

Copy after login

Number nesting

Large numbers are nested within medium numbers, and medium numbers are nested within small numbers.

#html
<h1>大标题</h1>
<p>文字1</p>
<p>文字2</p>
<p>文字3</p>
<h1>大标题</h1>
<p>文字1</p>
<p>文字2</p>
<p>文字3</p>
<h1>大标题</h1>
<p>文字1</p>
<p>文字2</p>
<p>文字3</p>

#css
h1::before{
    content:counter(h)&#39;.&#39;;
}
h1{
    counter-increment:h;
}
p::before{
    content:counter(p)&#39;.&#39;;
    margin-left:40px;
}
p{
    counter-increment:p;
}

Copy after login

It can be found in the output of the example that the numbers of p are consecutive. If you renumber the three p's after each h1, you can use the counter-reset attribute to reset it. Modifying the css of the above h1:

h1{    
    counter-increment:h;    
    counter-reset:p;
}

Copy after login

can also achieve more complex nesting, such as three-level nesting. .

#html
<h1>大标题</h1>
<h2>中标题</h2>
<h3>小标题</h3>
<h3>小标题</h3>
<h2>中标题</h2>
<h3>小标题</h3>
<h3>小标题</h3>
<h1>大标题</h1>
<h2>中标题</h2>
<h3>小标题</h3>
<h3>小标题</h3>
<h2>中标题</h2>
<h3>小标题</h3>
<h3>小标题</h3>

#css
h1::before{
    content:counter(h1)&#39;.&#39;;
}
h1{
    counter-increment:h1;
    counter-reset:h2;
}
h2::before{
    content:counter(h1) &#39;-&#39; counter(h2);
}
h2{
    counter-increment:h2;
    counter-reset:h3;
    margin-left:40px;
}
h3::before{
    content:counter(h1) &#39;-&#39; counter(h2) &#39;-&#39; counter(h3);
}
h3{
    counter-increment:h3;
    margin-left:80px;
}

Copy after login

The complete DEMO is given below

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS content</title>
<style>
.string p:after {
    margin-left: -16px;
    background: #fff;
    content: "支持";
    color: #f00;
}

.attr p:after {
    content: attr(title);
}

.url p:before {
    content: url(https://img.php.cn/upload/article/000/000/009/587d87ecca52d563.jpg);
    display: block;
}

.test ol {
    margin: 16px 0;
    padding: 0;
    list-style: none;
}

.counter1 li {
    counter-increment: testname;
}

.counter1 li:before {
    content: counter(testname)":";
    color: #f00;
    font-family: georgia,serif,sans-serif;
}

.counter2 li {
    counter-increment: testname2;
}

.counter2 li:before {
    content: counter(testname2,lower-roman)":";
    color: #f00;
    font-family: georgia,serif,sans-serif;
}

.counter3 ol ol {
    margin: 0 0 0 28px;
}

.counter3 li {
    padding: 2px 0;
    counter-increment: testname3;
}

.counter3 li:before {
    content: counter(testname3,float)":";
    color: #f00;
    font-family: georgia,serif,sans-serif;
}

.counter3 li li {
    counter-increment: testname4;
}

.counter3 li li:before {
    content: counter(testname3,decimal)"."counter(testname4,decimal)":";
}

.counter3 li li li {
    counter-increment: testname5;
}

.counter3 li li li:before {
    content: counter(testname3,decimal)"."counter(testname4,decimal)"."counter(testname5,decimal)":";
}
</style>
</head>
<body>
<ul>
    <li>
        <strong>string：</strong>
        <p>你的浏览器是否支持content属性：否</p>
    </li>
    <li>
        <strong>attr：</strong>
        <p title="如果你看到我则说明你目前使用的浏览器支持content属性"></p>
    </li>
    <li>
        <strong>url()：</strong>
        <p>如果你看到图片则说明你目前使用的浏览器支持content属性</p>
    </li>
    <li>
        <strong>counter(name)：</strong>
        <ol>
            <li>列表项</li>
            <li>列表项</li>
            <li>列表项</li>
        </ol>
    </li>
    <li>
        <strong>counter(name,list-style-type)：</strong>
        <ol>
            <li>列表项</li>
            <li>列表项</li>
            <li>列表项</li>
        </ol>
    </li>
    <li>
        <strong>counter(name)拓展应用：</strong>
        <ol>
            <li>列表项
                <ol>
                    <li>列表项
                        <ol>
                            <li>列表项</li>
                            <li>列表项</li>
                        </ol>
                    </li>
                    <li>列表项</li>
                </ol>
            </li>
            <li>列表项
                <ol>
                    <li>列表项</li>
                    <li>列表项</li>
                </ol>
            </li>
            <li>列表项
                <ol>
                    <li>列表项</li>
                    <li>列表项</li>
                </ol>
            </li>
        </ol>
    </li>
</ul>
</body>
</html>

Copy after login