textarea高度自适應，随着内容增加高度增加

$(function(){
        $.fn.autoHeight = function(){    
        function autoHeight(elem){
            elem.style.height = 'auto';
            elem.scrollTop = 0; //防抖動
            elem.style.height = elem.scrollHeight + 'px';
        }
        this.each(function(){
            autoHeight(this);
            $(this).on('keyup', function(){
                autoHeight(this);
            });
        });     
    }                
    $('textarea[autoHeight]').autoHeight();    
})

頁面中的textarea直接加屬性就行

<textarea  autoHeight="true" readonly="readonly" > </textarea>

pc   移動端都經過測試，沒問題 放心用吧！
           

轉載自https://www.cnblogs.com/purple04551/p/8075366.html