vault backup: 2024-10-12 17:19:45

03-UnrealEngine/Gameplay/UObject/UnrealSpecifiers/Meta/Blueprint/HiddenNode/HiddenNode.md

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+# HiddenNode
+
+- **功能描述：** 把指定的UBTNode隐藏不在右键菜单中显示。
+- **使用位置：** UCLASS
+- **引擎模块：** Blueprint
+- **元数据类型：** bool
+- **限制类型：** UBTNode
+- **常用程度：** ★
+
+把指定的UBTNode隐藏不在右键菜单中显示。
+
+## 测试代码：
+
+```cpp
+
+UCLASS(MinimalAPI,meta = ())
+class UMyBT_NotHiddenNode : public UBTDecorator
+{
+	GENERATED_UCLASS_BODY()
+
+	UPROPERTY(Category = Node, EditAnywhere)
+	float MyFloat;
+};
+
+UCLASS(MinimalAPI,meta = (HiddenNode))
+class UMyBT_HiddenNode : public UBTDecorator
+{
+	GENERATED_UCLASS_BODY()
+
+	UPROPERTY(Category = Node, EditAnywhere)
+	float MyFloat;
+};
+
+```
+
+## 测试结果：
+
+可见只有UMyBT_NotHiddenNode 显示了出来，而UMyBT_HiddenNode 被隐藏了。
+
+![Untitled](Untitled.png)
+
+## 原理：
+
+原理比较简单，就是坚持元数据标记，然后设置bIsHidden 。
+
+```cpp
+bool FGraphNodeClassHelper::IsHidingClass(UClass* Class)
+{
+	static FName MetaHideInEditor = TEXT("HiddenNode");
+
+	return 
+		Class && 
+		((Class->HasAnyClassFlags(CLASS_Native) && Class->HasMetaData(MetaHideInEditor))
+		|| ForcedHiddenClasses.Contains(Class));
+}
+
+//D:\github\UnrealEngine\Engine\Source\Editor\AIGraph\Private\AIGraphTypes.cpp
+void FGraphNodeClassHelper::BuildClassGraph()
+{
+		for (TObjectIterator<UClass> It; It; ++It)
+		{
+			UClass* TestClass = *It;
+			if (TestClass->HasAnyClassFlags(CLASS_Native) && TestClass->IsChildOf(RootNodeClass))
+			{
+				
+				NewData.bIsHidden = IsHidingClass(TestClass);
+		
+				NewNode->Data = NewData;
+		
+				if (TestClass == RootNodeClass)
+				{
+					RootNode = NewNode;
+				}
+		
+				NodeList.Add(NewNode);
+			}
+		}
+}
+```