CSS3 content attribute implementation steps-CSS Tutorial-php.cn

CSS3 content attribute implementation steps

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Release： 2017-12-01 10:01:49

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We know that the pseudo-classes of :before" and ":after" appear in CSS3, so today we will teach you the steps to implement the content attribute of CSS3. The following is a case, let's take a look.

css3 appears in ":before", ":after" pseudo-classes,

You can write like this:

h1:after{
content:&#39;h1后插入的文本&#39;;
...}

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The functions and effects of these two selectors will not be introduced here. Let’s mainly talk about the css attribute content mentioned above, which is used with the :after and :before pseudo-elements to display content before or after the object.

The value of content:

##. #normal: Default value. Behavior is the same as none value. image, audio, video or any other resource supported by the browser) : Insert the string

counter(name): Use a named counter

counter(name,

list-style-type

): Use named counters and comply with the specified list-style-type attribute

counters(name,string): Use all named counters

counters(name,string,list-style-type): Use all named counters and comply with the specified list-style-type attribute

no-close-quote: Do not insert the post-tag of the quotes attribute . but increases its nesting level

no-open-quote: does not insert the before tag of quotes attribute but decreases its nesting level

close-quote: inserts the after tag of quotes attribute.

open-quote: Insert the pre-mark of the quotes attribute

The values that are difficult to understand here are: counter(name);

The following mainly summarizes this section , and finally a demo of each value will be given.

For example, I have the following html structure:

<ul>
<li>这个是有序列表</li>
<li>这个是有序列表</li>
<li>这个是有序列表</li>
<li>这个是有序列表</li>
<li>这个是有序列表</li></ul>

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I want to add the current li index value after each li:

ul li{
counter-increment:index;
}
ul li:after{
content:&#39;统计：&#39;counter(index);
display:block;
line-height:35px;
}

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Explanation:

count(name) The name here must be specified in advance, otherwise all values will be 0;

count(name,list-style-type) The list-style-type here is the value of the list-style-type attribute in css;

The complete DEMO is given below

<!DOCTYPE html><html><head><meta charset="utf-8"><title>CSS content</title><meta name="author" content="phpstudy.net"><meta name="copyright" content="www.phpstudy.net"><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://pic.cnblogs.com/avatar/779447/20160817152433.png);
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>如果你看到我的头像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>

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I believe you have read it You have mastered the methods in these cases. For more exciting information, please pay attention to other related articles on the PHP Chinese website!