> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# PFMultiplayerAllocateMemoryCallback

> PlayFab Multiplayer C/C++ 程式庫用於要求動態配置記憶體緩衝區之 PFMultiplayerAllocateMemoryCallback 的參考。

每次 PlayFab Multiplayer 程式庫必須動態配置新的記憶體緩衝區時叫用的回呼。

## 語法

```cpp theme={null}
typedef
void* (*PFMultiplayerAllocateMemoryCallback)(  
    size_t size,  
    uint32_t memoryTypeId  
)  
```

### 參數

**`size`**   size\_t

要進行之配置的大小。此值永遠不會為零。

**`memoryTypeId`**   uint32\_t

代表所配置記憶體之 PlayFab Multiplayer 程式庫內部類別的不透明識別碼。應忽略此值。

### 傳回值

類型：void\*

指向指定大小之已配置記憶體區塊的指標；如果配置失敗，則為 nullptr。

## 備註

此回呼可選擇性地使用 [PFMultiplayerSetMemoryCallbacks()](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/functions/pfmultiplayersetmemorycallbacks) 方法安裝。<br /><br /> 回呼必須配置並傳回一個指向指定大小之連續記憶體區塊的指標，此記憶體在叫用遊戲對應的 [PFMultiplayerFreeMemoryCallback](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/callbacks/pfmultiplayerfreememorycallback) 以釋放它之前都必須保持有效。如果無法做到，回呼必須傳回 nullptr 使配置失敗。記憶體配置失敗有時被視為無害，但通常會導致目前的 PlayFab Multiplayer 程式庫作業失敗。   <br /><br /> 此方法傳回的每個非 nullptr 值，在不再需要該記憶體時，都會隨後傳遞給對應的 [PFMultiplayerFreeMemoryCallback](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/callbacks/pfmultiplayerfreememorycallback)。

## 需求

**標頭：** PFMultiplayer.h

## 另請參閱

[PFMultiplayer 成員](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/pfmultiplayer_members)\
[PFMultiplayerFreeMemoryCallback](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/callbacks/pfmultiplayerfreememorycallback)\
[PFMultiplayerSetMemoryCallbacks](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/functions/pfmultiplayersetmemorycallbacks)


## Related topics

- [PFMultiplayerFreeMemoryCallback](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/callbacks/pfmultiplayerfreememorycallback.md)
- [PFMultiplayerSetMemoryCallbacks](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/functions/pfmultiplayersetmemorycallbacks.md)
- [PFMultiplayer C/C++ API 概觀 - PFMultiplayer.h](/zh-TW/services/playfab/multiplayer/lobby/playfabmultiplayerreference-cpp/pfmultiplayer/pfmultiplayer_members.md)
- [PartyAllocateMemoryCallback](/zh-TW/services/playfab/multiplayer/networking/reference/callbacks/partyallocatememorycallback.md)
- [game_chat_allocate_memory_callback](/zh-TW/reference/chat/gamechat2/functions/game_chat_allocate_memory_callback.md)