虚幻引擎5 GAS开发俯视角RPG游戏 P05-08 UI 部件数据表

1.目标:创建一个数据表,存储一些标签信息

Source/CC_Aura/Public/UI/WidgetController/CC_OverlayWidgetController.h:

cpp 复制代码

/*数据表行结构:用于存储标签信息*/
USTRUCT(BlueprintType)
struct FUIWidgetRow : public FTableRowBase
{
	GENERATED_BODY()

	UPROPERTY(EditAnywhere, BlueprintReadOnly)
	FGameplayTag MessageTag = FGameplayTag();		//标签

	UPROPERTY(EditAnywhere, BlueprintReadOnly)
	FText Message = FText();						//描述
	
	UPROPERTY(EditAnywhere, BlueprintReadOnly)
	TSubclassOf<UCC_UserWidget> MessageWidget;		//小部件

	UPROPERTY(EditAnywhere, BlueprintReadOnly)
	UTexture2D* Image = nullptr;					//图片
};

2.C++创建数据表指针:

cpp 复制代码

protected:
	/*消息部件数据表*/
	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category="Widget Data")
	TObjectPtr<UDataTable> MessageWidgetDataTable;

3.在BP_OverlayWidgetController里配置数据表:

(1)蓝图创建数据表:

(2)配置数据表:

4.定义一个模板函数,从标签中找到数据行:

cpp 复制代码

/*通过标签查找数据表行*/
	template<typename T>
	T* GetDataTableRowByTag(UDataTable* DataTable, const FGameplayTag& Tag);

cpp 复制代码

template <typename T>
T* UCC_OverlayWidgetController::GetDataTableRowByTag(UDataTable* DataTable, const FGameplayTag& Tag)
{
	return DataTable->FindRow<T>(Tag.GetTagName(), TEXT(""));
}

CC_OverlayWidgetController.cpp:

有红线,报错.这是因为Lambda函数是匿名函数,需要在[ ]里添加"this":

cpp 复制代码

CC_AbilitySystemComponent->OnEffectAssetTags.AddLambda(
		[this](const FGameplayTagContainer& AssetTags)
		{
			for(const FGameplayTag& Tag : AssetTags)
			{
				//对标签进行检测，如果不是信息标签，将无法进行广播
				FGameplayTag RequestGameplayTag = FGameplayTag::RequestGameplayTag(FName("Message"));
				if (Tag.MatchesTag(RequestGameplayTag))		//检测Tag是否是RequestGameplayTag的子标签
				{
					FUIWidgetRow* Row = GetDataTableRowByTag<FUIWidgetRow>(MessageWidgetDataTable, Tag);
				}
			}
		}
	);

5.现在我们的目的是:将数据表的行信息,广播给小部件

(1)所以,创建一个动态多播委托:

cpp 复制代码

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FOnMessageWidgetRowSignature, FUIWidgetRow, Row);

(2)定义委托

cpp 复制代码

	/*委托:消息行*/
	UPROPERTY(BlueprintAssignable, Category="GAS|Messages")
	FOnMessageWidgetRowSignature OnMessageWidgetRowSignature;

(3)广播值的变化:

6.打开蓝图WBP_Overlay:

绑定委托事件:

7.GameplayEffect里添加标签:

完美