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03-UnrealEngine/Gameplay/UObject/UnrealSpecifiers/Meta/GAS/HideFromModifiers/HideFromModifiers.md

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+# HideFromModifiers
+
+- **功能描述：** 指定AttributeSet下的某属性不出现在GameplayEffect下的Modifiers的Attribute选择里。
+- **使用位置：** UPROPERTY
+- **引擎模块：** GAS
+- **元数据类型：** bool
+- **限制类型：** UAttributeSet下的属性
+- **关联项：** [HideInDetailsView](../HideInDetailsView/HideInDetailsView.md)
+- **常用程度：** ★★★
+
+指定AttributeSet下的某属性不出现在GameplayEffect下的Modifiers的Attribute选择里。
+
+## 测试代码：
+
+```cpp
+UCLASS()
+class UMyAttributeSet : public UAttributeSet
+{
+	GENERATED_BODY()
+public:
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Core")
+	float HP = 100.f;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Core", meta = (HideInDetailsView))
+	float HP_HideInDetailsView = 100.f;
+
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Core", meta = (HideFromModifiers))
+	float HP_HideFromModifiers = 100.f;
+};
+UCLASS()
+class UMyAttributeSetTest : public UObject
+{
+	GENERATED_BODY()
+public:
+	UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "GAS")
+	FGameplayAttribute MyAttribute;
+};
+```
+
+## 测试结果：
+
+在蓝图中创建一个GameplayEffect，然后观察其Modifiers下的Attribute选择。
+
+发现HP_HideFromModifiers 可以出现在正常的FGameplayAttribute 选项卡中，但不能出现在Modifiers下的Attribute选项卡里。这就是这里的作用。
+
+![Untitled](Untitled.png)
+
+## 原理：
+
+在FGameplayModifierInfo的Attribute属性上有FilterMetaTag的元数据，然后取出其里面的值，最终还是传到GetAllAttributeProperties作为FilterMetaStr来过滤。因此属性上出现HideFromModifiers就不能出现。
+
+```cpp
+USTRUCT(BlueprintType)
+struct GAMEPLAYABILITIES_API FGameplayModifierInfo
+{
+	GENERATED_USTRUCT_BODY()
+	
+	/** The Attribute we modify or the GE we modify modifies. */
+	UPROPERTY(EditDefaultsOnly, Category=GameplayModifier, meta=(FilterMetaTag="HideFromModifiers"))
+	FGameplayAttribute Attribute;
+};
+
+void FAttributePropertyDetails::CustomizeHeader( TSharedRef<IPropertyHandle> StructPropertyHandle, class FDetailWidgetRow& HeaderRow, IPropertyTypeCustomizationUtils& StructCustomizationUtils )
+{
+		const FString& FilterMetaStr = StructPropertyHandle->GetProperty()->GetMetaData(TEXT("FilterMetaTag"));
+	SNew(SGameplayAttributeWidget)
+	.OnAttributeChanged(this, &FAttributePropertyDetails::OnAttributeChanged)
+	.DefaultProperty(PropertyValue)
+	.FilterMetaData(FilterMetaStr)
+}
+void FGameplayAttribute::GetAllAttributeProperties(TArray<FProperty*>& OutProperties, FString FilterMetaStr, bool UseEditorOnlyData)
+{}
+```