<form id="form1" runat="server">
<div>
<textarea id='textarea' name="textarea" onpropertychange='setTareaAutoHeight("textarea")' oninput='setTareaAutoHeight("textarea")' style="100%; overflow-y:hidden; border:0; font-size:12px"><asp:Literal ID="litCont" runat="server"></asp:Literal></textarea>
<!--
IE支持 onPropertyChange 火狐支持oninput
Firefox有个oninput事件效果和onPropertyChange一样，所以同时加上oninput和onPropertyChange问题就解决
-->
</form>
</body>
function init() {
// 设置textarea自适应高度
var handler = function () {
setTareaAutoHeight('textarea');
};
// 添加监听
if (window.addEventListener) {//FF
window.addEventListener('DOMContentLoaded', handler, false);
window.addEventListener('load', handler, false);
} else if (window.attachEvent)//IE
window.attachEvent('onload', handler);
else
window.onload = handler;
} // end init
init();
function setTareaAutoHeight(id) {
document.getElementById(id).style.height = document.getElementById(id).scrollHeight + "px";
}