jQuery自动截取文字长度，超过部分

<html>
<head>
    <meta charset="utf-8">
    <script src="js/jquery-1.11.0.js"></script>


<script type="text/javascript">
//返回val的字节长度
function getByteLen(val) {
var len = 0;
for (var i = 0; i < val.length; i++) {
if (val[i].match(/[^x00-xff]/ig) != null) //全角
len += 2;
else
len += 1;
}
return len;
}
//返回val在规定字节长度max内的值
function getByteVal(val, max) {
var returnValue = '';
var byteValLen = 0;
for (var i = 0; i < val.length; i++) {
if (val[i].match(/[^x00-xff]/ig) != null)
byteValLen += 2;
else
byteValLen += 1;
if (byteValLen > max)
break;
returnValue += val[i];
}
return returnValue;
}
$(function() {
var _area = $('textarea#txtPrizeNote');
var _info = _area.next();
var _max = _area.attr('maxlength');
var _val;
_area.bind('keyup change', function() { //绑定keyup和change事件
if (_info.find('span').size() < 1) {//避免每次弹起都会插入一条提示信息
_info.append(_max);
}
_val = $(this).val();
_cur = getByteLen(_val);
if (_cur == 0) {//当默认值长度为0时,可输入数为默认maxlength值
_info.text(_max);
} else if (_cur < _max) {//当默认值小于限制数时,可输入数为max-cur
_info.text(_max - _cur);
} else {//当默认值大于等于限制数时
_info.text(0);
$(this).val(getByteVal(_val,_max)); //截取指定字节长度内的值
}
});
});
</script


</head>
<body>

<div>
<textarea id="txtPrizeNote" runat="server" height="74px" width="480px" maxlength="10"
style=" 480px; height: 74px; float: left"></textarea>
<span style="color: Red;">*</span><br />
剩余字数：<span id="showmsg" style="color: red"></span>
</div>
</body>

</html>//搜索字符限制

第二种

//超出的文字自动+省略号

jQuery.fn.limit=function(){

var self = $("*[limit]");

self.each(

function(){

var objString = $.trim($(this).text());

var objLength = $.trim($(this).text()).length;

var num = $(this).attr("limit");

if(objLength > num){

$(this).attr("title",objString);

objString = $(this).text(objString.substring(0,num) + "..");

}

);

};

$("*[limit]").limit();