這篇文章主要介紹了Lua獲取utf8字符串長度和字符串截取並用...代替,本文直接給出兩個函數的實現代碼,需要的朋友可以參考下
一、LUA獲取utf8字符串長度
代碼如下:
--- 獲取utf8編碼字符串正確長度的方法
-- @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、截取給定字符串的部分長度，超出部分用省略號“.”替換
代碼如下:
--@brief 切割字符串，並用“...”替換尾部
--@param sName:要切割的字符串
--@return nMaxCount，字符串上限,中文字為2的倍數
--@param nShowCount：顯示英文字個數，中文字為2的倍數,可為空
--@note 函數實現：截取字符串一部分，剩余用“...”替換
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
