# UInputCommandData

## 基本信息
- **类型**: UCLASS(BlueprintType)
- **父类**: UDataAsset
- **源文件**: Plugins/CharacterControl/Source/CharacterControl/Public/InputCommandData.h
- **模块**: CharacterControl

## 功能概述
UDataAsset container for input configuration. Holds InputMappingContext (Enhanced Input mapping context to load) and InputCommands (TArray<FInputCommand>, the action-to-command mappings). Pure data container with no runtime logic.

## 设计用意
Standard UE data asset pattern for designer-friendly configuration. Designer creates asset, fills in mappings, assigns to UCommandInputComponent::CommandData. Decouples configuration from code.

## 职责范围
Configuration data container. Holds mapping context reference and command array. No runtime logic (empty .cpp file).

## 项目内依赖
| 依赖项 | 关系 | 源文件 |
|--------|------|--------|
| FInputCommand | 包含 (TArray成员) | Plugins/CharacterControl/Source/CharacterControl/Public/InputCommandData.h |
| CommandEndpoint.h | #include (for FDiscreteMeta) | Plugins/CharacterControl/Source/CharacterControl/Public/CommandEndpoint.h |

## 对外接口
UInputCommandData 是 UDataAsset 子类，纯数据容器，无运行时逻辑。在 Content Browser 中创建资产，通过资产编辑器配置输入映射。所有属性为 EditAnywhere BlueprintReadOnly，设计师可在编辑器中填写。

- **InputMappingContext** (TObjectPtr<UInputMappingContext>, EditAnywhere, BlueprintReadOnly): 指向 Enhanced Input 的 InputMappingContext 资产。UCommandInputComponent::BeginPlay 将此上下文加载到 EnhancedInputLocalPlayerSubsystem
- **InputCommands** (TArray<FInputCommand>, EditAnywhere, BlueprintReadOnly): FInputCommand 数组，每个条目定义一条 InputAction 到命令的映射。包含：InputAction 引用、bIsContinuous 开关、ContinousCommandTag（连续标签）、DiscreteCommandMeta（离散元数据）

创建资产后将其赋值给 UCommandInputComponent::CommandData 属性即可激活。多个 UCommandInputComponent 可共享同一个 UInputCommandData 资产。

## 使用方法
UInputCommandData 是设计时配置资产，运行时由 UCommandInputComponent 消费：

- **定义**: `Plugins/CharacterControl/Source/CharacterControl/Public/InputCommandData.h:31-40` -- UCLASS(BlueprintType) UDataAsset 子类，两个 UPROPERTY
- **读取 InputMappingContext**: `Plugins/CharacterControl/Source/CharacterControl/Private/CommandInputComponent.cpp:26-29` -- CommandData->InputMappingContext 传给 Subsystem->AddMappingContext
- **读取 InputCommands**: `Plugins/CharacterControl/Source/CharacterControl/Private/CommandInputComponent.cpp:96` -- 遍历 `CommandData->InputCommands` 数组
- **消费 FInputCommand 字段**: `Plugins/CharacterControl/Source/CharacterControl/Private/CommandInputComponent.cpp:41-80` -- BuildPacket 读取每个 FInputCommand 的各字段构建 FCommandPacket
- **空实现**: `Plugins/CharacterControl/Source/CharacterControl/Private/InputCommandData.cpp` -- .cpp 文件只包含 include，无任何实现，确认为纯数据资产

## 用例
- **设计师配置流程**: 在 Content Browser 中右键创建 UInputCommandData 资产，配置 InputMappingContext 指向已有的 Enhanced Input 映射上下文。在 InputCommands 数组中添加条目：选择 InputAction，设置 bIsContinuous，填入 GameplayTag，配置 DiscreteCommandMeta 的匹配规则。最后将资产赋值给 PlayerController 上的 UCommandInputComponent::CommandData
- **InputMappingContext 加载**: `Plugins/CharacterControl/Source/CharacterControl/Private/CommandInputComponent.cpp:26-29` -- BeginPlay 从 CommandData 读取 InputMappingContext 并通过 Subsystem->AddMappingContext 加载
- **InputCommands 数组遍历**: `Plugins/CharacterControl/Source/CharacterControl/Private/CommandInputComponent.cpp:96-114` -- BindAllCommands 遍历 CommandData->InputCommands，对每条 FInputCommand 执行输入绑定
- **多组件共享资产**: 同一 UInputCommandData 资产可被多个 UCommandInputComponent 引用，实现配置复用