释放双眼，带上耳机，听听看~！
移动端要引入一个插件
地址：https://github.com/zenorocha/clipboard.js/wiki/CDN-Providers
<script src="https://cdnjs.admincdn.com/clipboard.js/2.0.0/clipboard.min.js"></script> <input id="copycode" class="main-code" readonly value="" > <button class="main-btn" data-clipboard-target="#copycode" data-clipboard-action="copy">复制</button>
js：
<script type="text/javascript">
var copyBtn = new ClipboardJS('.main-btn');
// console.log(copyBtn)
copyBtn.on("success",function(element){
// 复制成功
alert("已复制好，可贴粘");
element.clearSelection();
});
copyBtn.on("error",function(element){
//复制失败；
console.log( "复制失败，请手动复制" )
});
</script>
