槽位变更只走原子方法

经验

1. 下标 = 视觉格子，空槽是合法状态。定长 9 槽，inventory[i]=nil 即第 i 格空着，中间允许空。任何"把物品往前挪/压缩/重排"的操作都会让"你看到的格子"和"数组真实下标"脱节 → 物品消失。渲染直映 inventory[i]，数据层绝不重排。
2. 稀疏表禁用 #。带 nil 洞的表 #inv 是未定义的（可能=0 直接读成空包，或=洞前边界）。所有遍历上界一律 PlayerComponent.GetInventorySlots()。
3. 槽位变更只走原子方法，UI 不直接 poke 数组；拖拽落点用「命中槽=槽位操作矩阵 / 未命中槽=丢脚底」分流，命中靠全局像素坐标反查（底部物品栏无 zoom，与 event.x/y 同空间，不需要二次加减 GetVisualRect 偏移）。

关键代码

一、数据层：非压缩规整（消失 bug 的核心修复点）

lua
local INVENTORY_SLOTS = 9   -- 定长槽位数

--- 规整为定长数组（非压缩）：保留每个槽位的位置与 nil，仅截断超长、补 nil。
--- 绝不前移——下标即视觉格子，空槽必须保留。禁止用 #inv。
local function EnsureSlots(player)
    local inv = player.inventory
    if type(inv) ~= "table" then inv = {} end
    local slots = {}
    for s = 1, INVENTORY_SLOTS do
        slots[s] = inv[s]          -- ★ 原样复制，nil 也复制，位置不动
    end
    player.inventory = slots
    return slots
end

旧版是 for i=1,#inv do if inv[i] then valid[#valid+1]=inv[i] end end —— 既用了不可靠的 #inv，又把非 nil 项前移，正是元凶。

lua
function PlayerComponent.SanitizeInventory(player)
    if not player then return end
    local inv = player.inventory
    if type(inv) ~= "table" then inv = {} end
    for s = 1, INVENTORY_SLOTS do          -- ★ 固定 9 次，不用 #inv
        local item = inv[s]
        if item then
            local def = ItemRegistry.GetDef(item.id)
            if not def or not def.image or def.image == "" then
                inv[s] = nil               -- ★ 原地置 nil，好条目位置不变
            end
        end
    end
    local slots = {}
    for s = 1, INVENTORY_SLOTS do slots[s] = inv[s] end
    player.inventory = slots
end

二、槽位操作原子方法（落点矩阵的算子）

lua
-- 移动到空槽（目标非空返回 false，调用方改走 Swap）
function PlayerComponent.MoveInventoryToSlot(player, fromSlot, toSlot)
    local inv = EnsureSlots(player)
    if fromSlot == toSlot then return true end
    local item = inv[fromSlot]
    if not item then return false end
    if inv[toSlot] ~= nil then return false end
    inv[fromSlot] = nil
    inv[toSlot] = item
    return true
end

-- 两槽互换
function PlayerComponent.SwapInventorySlots(player, a, b)
    local inv = EnsureSlots(player)
    if a == b then return true end
    inv[a], inv[b] = inv[b], inv[a]
    return true
end

-- 手持 ↔ 指定槽 互换（原子）：手持物入槽；槽有可装备物则上手，否则回退/清手持
function PlayerComponent.SwapHeldWithSlot(player, slot)
    local inv = EnsureSlots(player)
    local heldId, heldObj = player.heldObjectType, player.heldObjectId
    if not heldId then return false end
    local slotItem = inv[slot]
    local def = ItemRegistry.GetDef(heldId)
    inv[slot] = { id = heldId, name = def and def.name or heldId,
        category = def and def.category or "其他",
        contrabandLevel = def and def.contrabandLevel or 0,
        sourceObjectId = heldObj }
    if slotItem then
        local sdef = ItemRegistry.GetDef(slotItem.id)
        if not sdef or not sdef.equipSlot then inv[slot] = slotItem; return false end
        player.heldObjectId = slotItem.sourceObjectId or ("inv:" .. slotItem.id)
        player.heldObjectType = slotItem.id
    else
        player.heldObjectId = nil; player.heldObjectType = nil
    end
    return true
end

三、UI 层：渲染直映 + 命中反查 + 落点矩阵

lua
local slotRefs_ = {}   -- 每次 Hotbar.Create 重建：{kind,idx,widget}

local function HitTestSlot(gx, gy)
    for i = 1, #slotRefs_ do
        local ref = slotRefs_[i]
        local vr = UI.GetVisualRect(ref.widget)   -- 与 event.x/y 同坐标空间
        if vr and gx >= vr.x and gx <= vr.x + vr.w
              and gy >= vr.y and gy <= vr.y + vr.h then
            return ref
        end
    end
    return nil
end

-- 渲染：直映 inventory[1..9]，nil 画空槽，并把每个槽 widget 登记身份
for i = 1, INVENTORY_SLOTS do
    local item = inventory[i]
    local def = item and ItemRegistry.GetDef(item.id) or nil
    if def and (not def.image or def.image == "") then def = nil end
    local slotWidget = CreateSlot(def, false, false,
        def and { fromInventory = i } or nil, onBagClick, context)
    slotRefs_[#slotRefs_ + 1] = { kind = "bag", idx = i, widget = slotWidget }
    bagChildren[#bagChildren + 1] = slotWidget
end
local handSlot = CreateSlot(heldDef, true, heldDef ~= nil, "held", onHandClick, context)
slotRefs_[#slotRefs_ + 1] = { kind = "hand", widget = handSlot }   -- 手持也算拖放目标

lua
local color = GHOST_BORDER_VALID                       -- 默认绿=丢脚底
local slotHit = HitTestSlot(gx, gy)
if slotHit then
    local src = dragState_.source
    local sameBag  = slotHit.kind == "bag"  and type(src)=="table" and src.fromInventory == slotHit.idx
    local sameHand = slotHit.kind == "hand" and src == "held"
    color = (sameBag or sameHand) and GHOST_BORDER_INVALID or GHOST_BORDER_SLOT  -- 红/蓝
end
-- 金色 GHOST_BORDER_TARGET 预留给"拖到小人=赠与"（未来）
ghost:SetBorderColor(color)

lua
local src = dragState_.source
local player = PlayerComponent.GetPlayer(state)
local slotHit = HitTestSlot(gx, gy)

if slotHit and player then
    if slotHit.kind == "bag" then
        if src == "held" then
            success = PlayerComponent.SwapHeldWithSlot(player, slotHit.idx)          -- 手持→背包
        elseif type(src) == "table" then
            if src.fromInventory == slotHit.idx then
                action = "cancel"                                                     -- 同槽
            elseif PlayerComponent.GetInventoryItem(player, slotHit.idx) then
                success = PlayerComponent.SwapInventorySlots(player, src.fromInventory, slotHit.idx)  -- 有物→换
            else
                success = PlayerComponent.MoveInventoryToSlot(player, src.fromInventory, slotHit.idx) -- 空→移
            end
        end
    elseif slotHit.kind == "hand" then
        if src == "held" then action = "cancel"                                       -- 手持→手持
        elseif type(src) == "table" then
            if PlayerComponent.HasHeldItem(player) then
                success = PlayerComponent.SwapHeldWithSlot(player, src.fromInventory) -- 背包↔手持(有物)
            else
                success = PlayerComponent.EquipFromInventory(player, src.fromInventory) -- 背包→手持(空)
            end
        end
    end
elseif not slotHit then
    -- 未命中任何槽 → 丢玩家脚底（读空间实时坐标，不反解屏幕）
    local fx, fy = ActorSpatialService.GetPosition(player.id)
    if fx and fy then
        success = require("系统.主角交互服务").DropItemAt(context, src, fx, fy)
    end
end

四、纪律：遍历上界 + 启动归一化

lua
-- 交互菜单（赠送/装备列表）：上界用槽位数，禁用 #player.inventory
for idx = 1, PlayerComponent.GetInventorySlots() do
    local item = player.inventory[idx]
    if item then ... end                       -- nil 槽跳过
end

-- main.lua 启动：一次性清脏数据并归一化为定长（之后运行期不再重排）
local _pchar = PlayerComponent.GetPlayer(context_.store.GetState())
if _pchar then PlayerComponent.SanitizeInventory(_pchar) end

排错复盘：为什么"第 9 格、有时第 4 格"会消失

验证