在Lua中计算含中文的字符串的长度

 --[[
     @desc: 计算字符串字符个数
     author:{author}
     time:-- ::
     --@inputstr: 源字符串
     return 字符个数
 ]]
 function getStringCharCount(str)
     local lenInByte = #str
     local charCount =
     local i =
     while (i <= lenInByte)
     do
         local curByte = string.byte(str, i)
         local byteCount = ;
         if curByte >  and curByte <=  then
             byteCount =                                                --1字节字符
         elseif curByte >=  and curByte <  then
             byteCount =                                                --双字节字符
         elseif curByte >=  and curByte <  then
             byteCount =                                                --汉字
         elseif curByte >=  and curByte <=  then
             byteCount =                                                --4字节字符
         end

         local char = string.sub(str, i, i + byteCount - )
         i = i + byteCount                                               -- 重置下一字节的索引
         charCount = charCount +                                        -- 字符的个数（长度）
     end
     return charCount
 end