/**
* 获取字符串字节长度
* @param {String}
* @returns {Boolean}
*/
function checkLength(v) {
var realLength = 0;
var len = v.length;
for (var i = 0; i < len; i++) {
var charCode = v.charCodeAt(i);
if (charCode >= 0 && charCode <= 128) realLength += 1;
else realLength += 2;
}
return realLength;
}