//自适应
$('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';
});
转载自:https://blog.csdn.net/qq_35607510/article/details/74331305