js
<textarea name="textarea" id="textarea" style='overflow-y: hidden;height:20px' onpropertychange="this.style.height = this.scrollHeight + 'px';" oninput="this.style.height = this.scrollHeight + 'px';"></textarea> <script> //拿到TextArea的DOM var textarea=document.getElementById('textarea'); //设置高度 textarea.style.height = textarea.scrollHeight + 'px'; </script>