java web-1.5CSS选择器

港控/mmm° 2023-07-07 08:14 55阅读 0赞

## CSS语法格式 ##

**格式**

选择器{
    	属性名1：属性值1；
    	属性名2：属性值2；
    	...
    }

选择器分类：基础选择器（id选择器，元素选择器，类选择器），扩展选择器  
选择器： 筛选具有相似特征的元素  
注意：每一对属性需要;隔开，最后一对不需要  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 1]  
**选择器**：

*  **分类**：  
    1.基础选择器  
    （1）id选择器: 选择器具体的id属性值的元素。 语法：\#id属性值\{\}  
    建议在一个html页面中id值唯一  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 2]  
    （2）元素选择器：选择具有相同标签名称的元素。语法：标签名称\{\}  
    注意：id选择器优先级高于元素选择器  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 3]  
    （3）类选择器：选择具有相同class属性值的元素。语法：.class属性值\{\}  
    注意：类选择器优先级高于元素选择器![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 4]  
    2.扩展选择器  
    （1）选择所有元素：语法：\*\{\}  
    （2）并集选择器：语法：选择器1，选择器2\{\}  
    （3）子选择器：筛选选择器1元素下的选择器2元素。语法：选择器1 选择器2\{\}![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 5]  
    （4）父选择器：筛选选择器2的父元素选择器1。语法：选择器1>选择器2\{\}  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 6]  
    （5）属性选择器：选择元素名称，属性名=属性值元素。语法：元素名称\[属性名=“属性值”\]\{\}![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 7]  
    （6）伪类选择器：选择一些元素具有的状态。语法：元素：状态\{\}  
    例如：的状态  
    \- link:初始化的状态。  
    \- visited：被访问过的状态。  
    \- active：正在访问的状态  
    \- hover：鼠标悬浮状态  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 8]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 9]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 10]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zOTc5NTA0OQ_size_16_color_FFFFFF_t_70 11]

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