第一步

在themes\yilia\source中新建js文件夹，在该文件夹中新建clipboard_use.js如下

$(".highlight").wrap("<div class='code-wrapper' style='position:relative'></div>");
/*页面载入完成后，创建复制按钮*/
!function (e, t, a) {
    /* code */
    var initCopyCode = function () {
        var copyHtml = '';
        copyHtml += '<button class="btn-copy" data-clipboard-snippet="">';
        copyHtml += '  <i class="fa fa-clipboard"></i><span>复制</span>';
        copyHtml += '</button>';
        $(".highlight .code").before(copyHtml);
        var clipboard = new ClipboardJS('.btn-copy', {
            target: function (trigger) {
                return trigger.nextElementSibling;
            }
        });
        clipboard.on('success', function (e) {
            e.trigger.innerHTML = "<i class='fa fa-clipboard'></i><span>复制成功</span>"
            setTimeout(function () {
                e.trigger.innerHTML = "<i class='fa fa-clipboard'></i><span>复制</span>"
            }, 1000)
           
            e.clearSelection();
        });
        clipboard.on('error', function (e) {
            e.trigger.innerHTML = "<i class='fa fa-clipboard'></i><span>复制失败</span>"
            setTimeout(function () {
                e.trigger.innerHTML = "<i class='fa fa-clipboard'></i><span>复制</span>"
            }, 1000)
            e.clearSelection();
        });
    }
    initCopyCode();
}(window, document);

第二步

在themes\yilia\layout\layout.ejs 文件的结尾处 （注意这个是body的结束标签）前插入如下代码：

<!-- 代码块复制功能开始 -->
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/clipboard@2.0.4/dist/clipboard.js"></script>
<script type="text/javascript" src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script type="text/javascript" src="/js/clipboard_use.js"></script>
<!-- 代码块复制功能结束 -->

第三步

在themes\yilia\source\main.0cf68a.css 最末尾添加如下代码：

.btn-copy {
    display: inline-block;
    position: absolute;
    right: 5px;
    top: 5px;
    cursor: pointer;
    background-color: #515151;
    border: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    -webkit-appearance: none;
    font-size: 13px;
    font-weight: 700;
    line-height: 20px;
    color: #d5d5d5;
    -webkit-transition: opacity .3s ease-in-out;
    -o-transition: opacity .3s ease-in-out;
    transition: opacity .3s ease-in-out;
    padding: 2px 6px;
}

.btn-copy span {
    margin-left: 5px
}

.code-wrapper .btn-copy:hover {
    color: #fff;
}

结果展示如图