js：
var txtobj={divName:"area", //外层容器的classtextareaName:"chackTextarea", //textarea的classnumName:"num", //数字的classnum: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classvar $textareaName=txtobj.textareaName; //textarea的classvar $numName=txtobj.numName; //数字的classvar $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0var 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='display:inline;color:red;font-weight:lighter' class="+$numName+">"+Math.abs($num-strlen)+"</b> 字"); //超出的样式}else{$par.html("还可以输入 <b style='display:inline;' class="+$numName+">"+($num-strlen)+"</b> 字"); //正常时候}$b.html($num-strlen); $("#areaLength").val(strlen);}$("."+$textareaName).live("focus",function(){$b=$(this).parents("."+$divname).find("."+$numName); //获取当前的数字$par=$b.parent(); $onthis=$(this); //获取当前的textareavar setNum=setInterval(numChange,500); });}textareaFn();
<div class="area"><div class="box01-num"><input type="hidden" name="areaLength" id="areaLength"/><p>你还可以输入<b style="display:inline;" class="num">140</b>字</p></div><div class="inputarea"><textarea class="chackTextarea" id="content" name="content" rows="15" ><s:property value='msgBo.content'/></textarea></div></div>
