++复制代码++ 代码如下:

<div class="area">
<p>
还可以输入<b class="num">140</b>字</p>
<textarea class="chackTextarea"></textarea>
</div>

<script type="text/javascript">
var txtobj = {
divName: "area", //外层容器的class
textareaName: "chackTextarea", //textarea的class
numName: "num", //数字的class
num: 140 //数字的最大数目
}
var textareaFn = function () {
//定义变量
var $onthis; //指向当前
var $divname = txtobj.divName; //外层容器的class
var $textareaName = txtobj.textareaName; //textarea的class
var $numName = txtobj.numName; //数字的class
var $num = txtobj.num; //数字的最大数目
function isChinese(str) { //判断是不是中文
var reCh = /[u00-uff]/;
return !reCh.test(str);
}
function numChange() {
var strlen = 0; //初始定义长度为0
var txtval = $.trim($onthis.val());
for (var i = 0; i < txtval.length; i++) {
if (isChinese(txtval.charAt(i)) == true) {
strlen = strlen + 2; //中文为2个字符
} else {
strlen = strlen + 1; //英文一个字符
}
}
strlen = Math.ceil(strlen / 2); //中英文相加除2取整数
if ($num - strlen < 0) {
$par.html("超出 <b style='color:red;font-weight:lighter' class=" + $numName + ">" + Math.abs($num - strlen) + "</b> 字"); //超出的样式
}
else {
$par.html("还可以输入 <b class=" + $numName + ">" + ($num - strlen) + "</b> 字"); //正常时候
}
$b.html($num - strlen);
}
$("." + $textareaName).live("focus", function () {
$b = $(this).parents("." + $divname).find("." + $numName); //获取当前的数字
$par = $b.parent();
$onthis = $(this); //获取当前的textarea
var setNum = setInterval(numChange, 500);
});
}
textareaFn();
</script>