jQuery - textarea 自适应内容高度

 <textarea id="textarea"></textarea>
 <script>
 function makeExpandingArea(el) {
     var setStyle = function(el) {
         el.style.height = 'auto';
         el.style.height = el.scrollHeight + 'px';
         // console.log(el.scrollHeight);
     }
     var delayedResize = function(el) {
         window.setTimeout(function() {
             setStyle(el);
         },
         0);
     }
     if (el.addEventListener) {
         el.addEventListener('input',function() {
             setStyle(el);
         },false);
         setStyle(el);
     } else if (el.attachEvent) {
         el.attachEvent('onpropertychange',function() {
             setStyle(el);
         });
         setStyle(el);
     }
     if (window.VBArray && window.addEventListener) { //IE9
         el.attachEvent("onkeydown",function() {
             var key = window.event.keyCode;
             if (key == 8 || key == 46) delayedResize(el);
         });
         el.attachEvent("oncut",function() {
             delayedResize(el);
         }); //处理粘贴
     }
 }
 makeExpandingArea(textarea);
 </script>

觉得不好看可以自己进行美化，修改样式就行了