
 直接看代码吧,很简单,也很实用。
 代码如下:
autoresizing textareavar observe;
if (window.attachEvent) {
 observe = function (element, event, handler) {
 element.attachEvent('on'+event, handler);
 };
}
else {
 observe = function (element, event, handler) {
 element.addEventListener(event, handler, false);
 };
}
function init () {
 var text = document.getElementById('text');
 function resize () {
 text.style.height = 'auto';
 text.style.height = text.scrollHeight+'px';
 }
 /* 0-timeout to get the already changed text */
 function delayedResize () {
 window.setTimeout(resize, 0);
 }
 observe(text, 'change', resize);
 observe(text, 'cut', delayedResize);
 observe(text, 'paste', delayedResize);
 observe(text, 'drop', delayedResize);
 observe(text, 'keydown', delayedResize);
 text.focus();
 text.select();
 resize();
}
 script>