限制文本字节数的JS源代码程序

　　　做项目时自己写一段js给大家。关于文本限制字数的问题，在实际开发中经常用到;主要问题出现在对中文的限制，下面代码就解决关于限制字节数的校验问题;只要将此下代码保存到一个js文件中并引入到校验的页面中，便可使用!同时希望大家给与大力支持和宝贵意见，本人会在今后闲余之际，发表更多的好文章，谢谢!!

以下是引用片段：

/*

value: 值；

byteLength：数据库字节长度

title：字段中文名称

attribute：属性名称

使用方法说明：

添加 （1） onkeyup="limitLength(this.value,100,'名称','name')"

(2) id="name" 或【struts标签】styleId="name"

注意：id名称和 attribute属性名称要一样

例子：</p> <p>或</p> <p><input type="text" name="explain" id="explain" onkeyup="limitLength(value,5,'语义说明','explain')" ></p> <p>*/</p> <p>function limitLength(value, byteLength, title, attribute) {</p> <p>var newvalue = value.replace(/[^\x00-\xff]/g, "**");</p> <p>var length = newvalue.length;</p> <p>//当填写的字节数小于设置的字节数</p> <p>if (length * 1 <=byteLength * 1){</p> <p>return;</p> <p>}</p> <p>var limitDate = newvalue.substr(0, byteLength);</p> <p>var count = 0;</p> <p>var limitvalue = "";</p> <p>for (var i = 0; i < limitDate.length; i++) {</p> <p>var flat = limitDate.substr(i, 1);</p> <p>if (flat == "*") {</p> <p>count++;</p> <p>}</p> <p>}</p> <p>var size = 0;</p> <p>var istar = newvalue.substr(byteLength * 1 - 1, 1);//校验点是否为“×”</p> <p>//if 基点是×; 判断在基点内有×为偶数还是奇数</p> <p>if (count % 2 == 0) {</p> <p>//当为偶数时</p> <p>size = count / 2 + (byteLength * 1 - count);</p> <p>limitvalue = value.substr(0, size);</p> <p>} else {</p> <p>//当为奇数时</p> <p>size = (count - 1) / 2 + (byteLength * 1 - count);</p> 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