输入字符限制

来源：互联网发布：如何添加打印机端口编辑：程序博客网时间：2024/05/16 12:53

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head>
<script>
function checklen(obj){
var lenE = obj.value.length;
var lenC = 0;
//var CJK = obj.value.match(/[u4E00-u9FA5uF900-uFA2D]/g);
//if (CJK != null) lenC += CJK.length;
tno.innerText = obj.maxlength - lenC - lenE ;
tno2.innerText = lenE;
if (tno.innerText < 0) {

var tmp = 0
var cut = obj.value.substring(0, obj.maxlength);
for (var i=0; i<cut.length; i++){
tmp += /[u4E00-u9FA5uF900-uFA2D]/.test(cut.charAt(i)) ? 2 : 1;
if (tmp > obj.maxlength) ;

if(obj.maxlength==0)
{
    return false;
    }
}
obj.value = cut.substring(0, i);
}
}
function aaa()
{
    tno.innerText = s1.maxlength;
    tno2.innerText = "0";
    }
</script>
<body onload="aaa();">
<textarea name="s1" rows="5" cols="50" maxlength="10" onpropertychange="checklen(this)"></textarea>

输入<span id="tno2"></span>个字符,剩余<span id="tno"></span>个字符
</body>
</html>