教程分为两步，添加 css 样式和添加 js 代码即可如下

1.子比主题设置—>自定义代码—>自定义 CSS 样式：,添加以下 CSS 代码：

/* 
 *子比主题下载页面一键复制提取码功能 css 样式开始
 *请本 CSS 代码放置子比主题设置->全局&功能->自定义 CSS 样式中即可
 */
.but-download .badg {
  position: relative;
  cursor:pointer;
}

.but-download .badg::after {
  position: absolute;
  content: " ";
  width: 0;
  height: 0;
  top: -11px;
  left: 50%;
  -webkit-transform: translateX(-50%);
     -moz-transform: translateX(-50%);
      -ms-transform: translateX(-50%);
       -o-transform: translateX(-50%);
          transform: translateX(-50%);
  border-top: 10px solid rgb(236, 235, 235);
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  -webkit-transition: .3s;
  -o-transition: .3s;
  -moz-transition: .3s;
  transition: .3s;
  opacity: 0;
}

.but-download .badg::before {
  content: attr(data-before);
  position: absolute;
  width: 100px;
  height: 31px;
  top: -40px;
  left: 50%;
  -webkit-transform: translateX(-50%);
     -moz-transform: translateX(-50%);
      -ms-transform: translateX(-50%);
       -o-transform: translateX(-50%);
          transform: translateX(-50%);
  font-size: 14px;
  line-height: 31px;
  border-radius: 4px;
  color: #6c6a6a;
  background-color: rgb(236, 235, 235);
  text-align: center;
  -webkit-transition: .3s;
  -o-transition: .3s;
  -moz-transition: .3s;
  transition: .3s;
  opacity: 0;
}

.but-download .badg:hover::after,
.but-download .badg:hover::before {
  opacity: 1;
}
/* 
 *子比主题下载页面一键复制提取码功能 css 样式结束
 */

2.子比主题设置—>自定义代码—>自定义 javascript 代码：,添加以下 javascript 代码：

/* 
 *子比主题下载页面一键复制提取码功能 JavaScript 代码开始
 *请本 JavaScript 代码放置子比主题设置->全局&功能->自定义 javascript 代码中即可
 */
if(document.querySelectorAll(".but-download .badg")!=undefined){
     const reg = /[a-zA-z0-9]/ig;
    const copy1 = document.querySelectorAll(".but-download .badg");
    for (let i = 0; i < copy1.length; i++) {
      copy1[i].index = i;
      copy1[i].setAttribute("data-before", "点击复制");
      copy1[i].addEventListener("click", copyOperation);
      copy1[i].addEventListener("mouseout", copyOk);
    }

    function copyOperation() {
      var oInput = document.createElement("input");
      let text = this.innerText;
      text = text.match(reg).join("");
      oInput.value = text;
      document.body.appendChild(oInput);
      oInput.select();
      document.execCommand("Copy");
      oInput.className = "oInput";
      oInput.style.display = "none";
      this.setAttribute("data-before", "已复制");
    }
    function copyOk() {
      setTimeout(() => {
        this.setAttribute("data-before", "点击复制");
      }, 300)
    }
}
/* 
 *子比主题下载页面一键复制提取码功能 JavaScript 代码结束
 */