在Lua中计算含中文的字符串的长度

 1 --[[
 2     @desc: 计算字符串字符个数
 3     author:{author}
 4     time:2017-12-29 16:08:11
 5     --@inputstr: 源字符串
 6     return 字符个数
 7 ]]
 8 function getStringCharCount(str)
 9     local lenInByte = #str
10     local charCount = 0
11     local i = 1
12     while (i <= lenInByte) 
13     do
14         local curByte = string.byte(str, i)
15         local byteCount = 1;
16         if curByte > 0 and curByte <= 127 then
17             byteCount = 1                                               --1字节字符
18         elseif curByte >= 192 and curByte < 223 then
19             byteCount = 2                                               --双字节字符
20         elseif curByte >= 224 and curByte < 239 then
21             byteCount = 3                                               --汉字
22         elseif curByte >= 240 and curByte <= 247 then
23             byteCount = 4                                               --4字节字符
24         end
25         
26         local char = string.sub(str, i, i + byteCount - 1)
27         i = i + byteCount                                               -- 重置下一字节的索引
28         charCount = charCount + 1                                       -- 字符的个数（长度）
29     end
30     return charCount
31 end