Lua 错误:字符串预期，为零

Question

我需要脚本方面的帮助。我几乎尝试了所有方法，但我无法弄清楚问题是什么。我想look.lua检查一下是否str = str.."nIt's "..getPokemonAge(thing.uid).." old."返回 nil，然后忽略它并继续执行脚本。

这是我在控制台上遇到的错误：

[04/12/2012 20:43:42] [Error - CreatureScript Interface] 
[04/12/2012 20:43:42] data/creaturescripts/scripts/look.lua:onLook
[04/12/2012 20:43:42] Description: 
[04/12/2012 20:43:42] data/lib/011-string.lua:16: bad argument #1 to 'find' (string expected, got nil)
[04/12/2012 20:43:42] stack traceback:
[04/12/2012 20:43:42]   [C]: in function 'find'
[04/12/2012 20:43:42]   data/lib/011-string.lua:16: in function '(for generator)'
[04/12/2012 20:43:42]   data/lib/011-string.lua:16: in function 'explode'
[04/12/2012 20:43:42]   data/lib/age system.lua:2: in function 'getPokemonYears'
[04/12/2012 20:43:42]   data/lib/age system.lua:42: in function 'getPokemonAge'
[04/12/2012 20:43:42]   data/creaturescripts/scripts/look.lua:32: in function <data/creaturescripts/scripts/look.lua:1>

011-字符串.lua

local i, pos, tmp, t = 0, 1, "", {}
        for s, e in function() return string.find(str, sep, pos) end do
            tmp = str:sub(pos, s - 1):trim()
            table.insert(t, tmp)
            pos = e + 1
            i = i + 1
        end

看.lua

str = str.."nIt's "..getPokemonAge(thing.uid).." old."

年龄系统.lua

function getPokemonYears(pokeball)
local data = string.explode(getItemAttribute(pokeball, "pokeballinfo"), "/")
-- data[1] = dia, data[2] = mes, data[3] = ano
local yearnow = math.floor(tonumber(os.date("%Y")))
local monthnow = math.floor(tonumber(os.date("%m")))
local daynow = math.floor(tonumber(os.date("%d")))
local ano = math.floor(tonumber(data[3]))
local mes = math.floor(tonumber(data[2]))
local dia = math.floor(tonumber(data[1]))
local years = 0
if yearnow == ano then years = monthnow-mes end
if yearnow > ano then years = (12-mes) + monthnow end
return years
end
function getPokemonMonths(pokeball)
local data = string.explode(getItemAttribute(pokeball, "pokeballinfo"), "/")
local yearnow = math.floor(tonumber(os.date("%Y")))
local monthnow = math.floor(tonumber(os.date("%m")))
local daynow = math.floor(tonumber(os.date("%d")))
local ano = math.floor(tonumber(data[3]))
local mes = math.floor(tonumber(data[2]))
local dia = math.floor(tonumber(data[1]))
if (yearnow == ano) and (monthnow==mes) and (daynow<dia+2.5) then months = 0 end
if (yearnow == ano) and (monthnow==mes) and (daynow>dia+2.5) then months = (daynow-dia)/2.5 end
if (yearnow == ano) and (monthnow>mes) then months = math.floor((30-dia)/2.5) + daynow/2.5 end
if (yearnow > ano) then
days = math.floor(monthnow*30+daynow)
months = math.floor(days/2.5)
end
if tostring(months):len() > 3 then months2 = tonumber(string.sub(tostring(months), 1, 3))
else months2 = months end
return months
end

function getPokemonAge(pokeball)
return ""..getPokemonYears(pokeball).." year, "..getPokemonMonths(pokeball).." months"
end

Answer 1

我想我终于理解了你的问题，所以我将重新表述我是如何理解它的，你可以判断这是否是你想要的。

据我了解，您知道您的函数getPokemonAge有时会导致错误。其他几个人指出，此错误来自getItemAttribute(pokeball, "pokeballinfo")返回nil。

现在我认为您希望程序在生成文本时返回文本，但忽略可能发生的任何错误并在出现错误时返回nil。

这可以通过 pcall 来完成（看这里）。

在我对你的getPokemonAge-Function的部分重写中，我用pcall调用getPokemonAgeInternal（这是你的原始函数）。然后我只是检查结果并在错误时返回nil。

function getPokemonAgeInternal(pokeball)
    return ""..getPokemonYears(pokeball).." year, "..getPokemonMonths(pokeball).." months"
end
function getPokenmonAge(pokeball)
    success, value = pcall( getPokemonAgeInternal, pokeball )
    if ( success )
    then
        return value
    else
        return nil
    end
end

如果您想保护

它免受错误的影响，您可以将类似的代码应用于您的getPokemonYears -Function。

如果您的错误总是来自getItemAttribute(pokeball, "pokeballinfo") nil则不应使用 pcall，而只需检查该条件并在getItemAttribute(pokeball, "pokeballinfo") == nil时返回 nil 。