<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1">
<title></title>
</head>
<body>
<input value="12312312312132313131" placeholder="" id="txtContent" disabled="disabled" style="border: none;background: transparent;"/>
<input type="button" onClick="copyTxt()" value="复制" />
</body>
<script type="text/javascript">
function copyTxt(){
document.getElementById("txtContent").select(); // 选择对象
document.execCommand("Copy"); // 执行浏览器复制命令
}
</script>
</html>