文本域输入字数限制
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html 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 language="javascript">
function checklen(obj){
var lenE = obj.value.length;
var lenC = 0;
var CJK = obj.value.match(/[\u4E00-\u9FA5\uF900-\uFA2D]/g);
if (CJK != null) lenC += CJK.length;
tno.innerText = obj.maxlength - lenC - 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-\u9FA5\uF900-\uFA2D]/.test(cut.charAt(i)) ? 2 : 1;
if (tmp > obj.maxlength) break;
}
obj.value = cut.substring(0, i);
}
}
</script>
<body>
<textarea name="s1" rows="5" cols="50" maxlength="11" onpropertychange="checklen(this)"></textarea>
<br>共可输入10字符，还剩 <span id="tno"></span>个字符
</body>
</html>
TAG:
