方法1:
$('textarea').each(function?()?{ this.setAttribute('style',?'height:'?+?(this.scrollHeight)?+?'px;overflow-y:hidden;');}).on('input',?function?()?{ this.style.height?=?'auto'; this.style.height?=?(this.scrollHeight)?+?'px';});}
方法2:用div模擬textarea:。代碼如下。加上contenteditable屬性
<div?contenteditable="true"></div>