JS~字符串长度判断,超出进行自动截取(支持中文)

转自:http://www.cnblogs.com/lori/p/3907960.html

 

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<html>
<script src="http://common.cnblogs.com/script/jquery.js" type="text/javascript"></script>
 
<body>
    <input type="text" name="username" />
</body>
<script type="text/ecmascript">
 
    
    var GetLength = function (str) {
        ///<summary>获得字符串实际长度,中文2,英文1</summary>
        ///<param name="str">要获得长度的字符串</param>
        var realLength = 0, len = str.length, charCode = -1;
        for (var i = 0; i < len; i++) {
            charCode = str.charCodeAt(i);
            if (charCode >= 0 && charCode <= 128) realLength += 1;
            else realLength += 2;
        }
        return realLength;
    };
 
 
    //js截取字符串,中英文都能用 
    //如果给定的字符串大于指定长度,截取指定长度返回,否者返回源字符串。 
    //字符串,长度 
 
    /**
     * js截取字符串,中英文都能用
     * @param str:需要截取的字符串
     * @param len: 需要截取的长度
     */
    function cutstr(str, len) {
        var str_length = 0;
        var str_len = 0;
        str_cut = new String();
        str_len = str.length;
        for (var i = 0; i < str_len; i++) {
            a = str.charAt(i);
            str_length++;
            if (escape(a).length > 4) {
                //中文字符的长度经编码之后大于4 
                str_length++;
            }
            str_cut = str_cut.concat(a);
            if (str_length >= len) {
                str_cut = str_cut.concat("...");
                return str_cut;
            }
        }
        //如果给定字符串小于指定长度,则返回源字符串; 
        if (str_length < len) {
            return str;
        }
    }
$(function () {
     $("input[name=username]").bind('keyup', function () {
      if (GetLength($(this).val()) > 10) {
       $(this).val(cutstr($(this).val(), 10));
       return;
     }
  });
});
</script>
</html>

  

 

posted @   暗夜独游Jevil  阅读(544)  评论(0编辑  收藏  举报
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