lua获取限制字数后的字符串

最新推荐文章于 2023-02-24 10:54:20 发布

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该函数`GetCharNewStrByLimit`用于处理UTF-8编码的字符串，根据限制的字符数进行截取。它遍历字符串的字节，区分单字节和多字节字符，确保截取过程中不中断多字节字符。适用于需要限制输出文本长度的场景。


function GetCharNewStrByLimit(str,limitCharNum)
	local bytes = {str:byte(1,#str)}
	local length,begin,cutByteLength = 0,false,0
	for _, byte in ipairs(bytes) do
		if byte < 128 or byte >= 192 then
			begin = false
			length = length + 1
		elseif not begin then
			begin = true
			length = length + 1
			if  length > limitCharNum then
				cutByteLength = cutByteLength - 1
			end
		else
			if length > limitCharNum then
				cutByteLength = cutByteLength + 1
			end
		end
		if length <= limitCharNum then
			cutByteLength = cutByteLength + 1
		else
			break
		end
	end
	return string.sub(str,1,cutByteLength)
end