js修改元素样式的九种方式总结_Javascript

1.直接设置style的属性

style属性可以设置或返回元素的内联样式,对于更改同一个元素的同一种样式，设置style属性的优先级较高

语法：element.style.property = value
property为css属性名，如：color，margin。如果属性名原来包含“-”，则需转换为小驼峰形式，如：backgroundcolor，marginleft。

var box = document.queryselector('div')
box.style.color = "#fff" // 将元素中文字设置为白色 
box.style.marginleft = "100px" // 将元素左外边距设置为100px

某些情况用这个设置 !important值无效

如果属性有’-'号，就写成驼峰的形式（如textalign）如果想保留 - 号，就中括号的形式

element.style.height = '100px';

2.直接设置属性

只能用于某些属性，相关样式会自动识别

element.setattribute('height', 100);
element.setattribute('height', '100px');

3.设置style的属性

element.setattribute('style', 'height: 100px !important');

4.使用setproperty

如果要设置!important，推荐用这种方法设置第三个参数

element.style.setproperty('height', '300px', 'important');

5.改变class （推荐）

通过改变伪元素父级的class来动态更改伪元素的样式

element.classname = 'blue';
element.classname += 'blue fb';

6.设置csstext

element.style.csstext = 'height: 100px !important';
element.style.csstext += 'height: 100px !important';

7.引入css样式文件

创建引入新的css样式文件

 function addnewstyle(newstyle) {
            var styleelement = document.getelementbyid('styles_js');

<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token operator">!</span>styleelement<span class="token punctuation">)</span> <span class="token punctuation">{<!-- --></span> styleelement <span class="token operator">&#61;</span> document<span class="token punctuation">.</span><span class="token function">createelement</span><span class="token punctuation">(</span><span class="token string">&#39;style&#39;</span><span class="token punctuation">)</span><span class="token punctuation">;</span> styleelement<span class="token punctuation">.</span>type <span class="token operator">&#61;</span> <span class="token string">&#39;text/css&#39;</span><span class="token punctuation">;</span> styleelement<span class="token punctuation">.</span>id <span class="token operator">&#61;</span> <span class="token string">&#39;styles_js&#39;</span><span class="token punctuation">;</span> document<span class="token punctuation">.</span><span class="token function">getelementsbytagname</span><span class="token punctuation">(</span><span class="token string">&#39;head&#39;</span><span class="token punctuation">)</span><span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span><span class="token punctuation">.</span><span class="token function">appendchild</span><span class="token punctuation">(</span>styleelement<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> styleelement<span class="token punctuation">.</span><span class="token function">appendchild</span><span class="token punctuation">(</span>document<span class="token punctuation">.</span><span class="token function">createtextnode</span><span class="token punctuation">(</span>newstyle<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token function">addnewstyle</span><span class="token punctuation">(</span><span class="token string">&#39;.box {height: 100px !important;}&#39;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

8.使用addrule、insertrule

// 在原有样式操作
        document.stylesheets[0].addrule('.box', 'height: 100px');
        document.stylesheets[0].insertrule('.box {height: 100px}', 0);

<span class="token comment">// 或者插入新样式时操作</span> <span class="token keyword">var</span> styleel <span class="token operator">&#61;</span> document<span class="token punctuation">.</span><span class="token function">createelement</span><span class="token punctuation">(</span><span class="token string">&#39;style&#39;</span><span class="token punctuation">)</span><span class="token punctuation">,</span> stylesheet <span class="token operator">&#61;</span> styleel<span class="token punctuation">.</span>sheet<span class="token punctuation">;</span> stylesheet<span class="token punctuation">.</span><span class="token function">addrule</span><span class="token punctuation">(</span><span class="token string">&#39;.box&#39;</span><span class="token punctuation">,</span> <span class="token string">&#39;height: 100px&#39;</span><span class="token punctuation">)</span><span class="token punctuation">;</span> stylesheet<span class="token punctuation">.</span><span class="token function">insertrule</span><span class="token punctuation">(</span><span class="token string">&#39;.box {height: 100px}&#39;</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> document<span class="token punctuation">.</span>head<span class="token punctuation">.</span><span class="token function">appendchild</span><span class="token punctuation">(</span>styleel<span class="token punctuation">)</span><span class="token punctuation">;</span>

9.通过classlist控制样式

classlist属性返回一个元素类属性集合（这里可以简单理解为类名的集合），通过使用classlist中的方法可以方便的访问和控制元素类名，达到控制样式的目的

classlist常用方法介绍：

名称	描述
`add(class1, class2, …)`	添加一个或多个类名
`remove(class1, class2, …)`	移除一个或多个类名
`replace(oldclass, newclass)`	替换类名
`contains(class)`	判定类名是否存在，返回布尔值
`toggle(class, true\|false)`	如果类名存在，则移除它，否则添加它，第二个参数代表无论类名是否存在，强制添加（`true`）或删除（`false`）

<div class="box">classlist test</div>
<script>
  var box = document.queryselector('.box')
  box.classlist.add('box1', 'box2')    // [box] => [box, box1, box2]
  box.classlist.remove('box1', 'box2') // [box, box1, box2] => [box]
  box.classlist.replace('box', 'box2')  // [box] => [box2]
  box.classlist.contains('box1')  // 当前元素不包含类名box1，返回false
  box.classlist.toggle('active')   // [box2] => [box2, active]
</script>