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