```html 1、抽取公共片段 <div th:fragment="copy"> &copy; 2011 The Good Thymes Virtual Grocery </div> 2、引入公共片段 <div th:insert="~{footer :: copy}"></div> ~{templatename::selector}：模板名::选择器 ~{templatename::fragmentname}:模板名::片段名 3、默认效果： insert的公共片段在div标签中 如果使用th:insert等属性进行引入，可以不用写~{}： 行内写法可以加上：[[~{}]];[(~{})]； ``` 三种引入公共片段的th属性： **th:insert**：将公共片段整个插入到声明引入的元素中 **th:replace**：将声明引入的元素替换为公共片段 **th:include**：将被引入的片段的内容包含进这个标签中 ```html <footer th:fragment="copy"> &copy; 2011 The Good Thymes Virtual Grocery </footer> 引入方式 <div th:insert="footer :: copy"></div> <div th:replace="footer :: copy"></div> <div th:include="footer :: copy"></div> 效果 <div> <footer> &copy; 2011 The Good Thymes Virtual Grocery </footer> </div> <footer> &copy; 2011 The Good Thymes Virtual Grocery </footer> <div> &copy; 2011 The Good Thymes Virtual Grocery </div> ``` 引入片段的时候传入参数： ```html <nav class="col-md-2 d-none d-md-block bg-light sidebar" id="sidebar"> <div class="sidebar-sticky"> <ul class="nav flex-column"> <li class="nav-item"> <a class="nav-link active" th:class="${activeUri=='main.html'?'nav-link active':'nav-link'}" href="#" th:href="@{/main.html}"> <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-home"> <path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"></path> <polyline points="9 22 9 12 15 12 15 22"></polyline> </svg> Dashboard <span class="sr-only">(current)</span> </a> </li> <!--引入侧边栏;传入参数--> <div th:replace="commons/bar::#sidebar(activeUri='emps')"></div> ```