这篇文章主要介绍了Lua获取utf8字符串长度和字符串截取并用...代替,本文直接给出两个函数的实现代码,需要的朋友可以参考下

一、LUA获取utf8字符串长度

代码如下:

--- 获取utf8编码字符串正确长度的方法

-- @param str

-- @return number

function utfstrlen(str)

local len = #str;

local left = len;

local cnt = 0;

local arr={0,0xc0,0xe0,0xf0,0xf8,0xfc};

while left ~= 0 do

local tmp=string.byte(str,-left);

local i=#arr;

while arr[i] do

if tmp>=arr[i] then left=left-i;break;end

i=i-1;

end

cnt=cnt+1;

end

return cnt;

end

二、截取给定字符串的部分长度，超出部分用省略号“.”替换

代码如下:

切割字符串，并用“...”替换尾部

sName:要切割的字符串

nMaxCount，字符串上限,中文字为2的倍数

nShowCount：显示英文字个数，中文字为2的倍数,可为空

函数实现：截取字符串一部分，剩余用“...”替换

function GetShortName(sName,nMaxCount,nShowCount)

if sName == nil or nMaxCount == nil then

return

end

local sStr = sName

local tCode = {}

local tName = {}

local nLenInByte = #sStr

local nWidth = 0

if nShowCount == nil then

nShowCount = nMaxCount - 3

end

for i=1,nLenInByte do

local curByte = string.byte(sStr, i)

local byteCount = 0;

if curByte>0 and curByte<=127 then

byteCount = 1

elseif curByte>=192 and curByte<223 then

byteCount = 2

elseif curByte>=224 and curByte<239 then

byteCount = 3

elseif curByte>=240 and curByte<=247 then

byteCount = 4

end

local char = nil

if byteCount > 0 then

char = string.sub(sStr, i, i+byteCount-1)

i = i + byteCount -1

end

if byteCount == 1 then

nWidth = nWidth + 1

table.insert(tName,char)

table.insert(tCode,1)

elseif byteCount > 1 then

nWidth = nWidth + 2

table.insert(tName,char)

table.insert(tCode,2)

end

end

if nWidth > nMaxCount then

local _sN = ""

local _len = 0

for i=1,#tName do

_sN = _sN .. tName[i]

_len = _len + tCode[i]

if _len >= nShowCount then

break

end

end

sName = _sN .. "..."

end

return sName

end

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