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

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+# HideThen
+
+- **功能描述：** 隐藏异步蓝图节点的Then引脚
+- **使用位置：** UCLASS
+- **元数据类型：** bool
+- **限制类型：** 蓝图异步节点
+- **关联项：** [ExposedAsyncProxy](../ExposedAsyncProxy/ExposedAsyncProxy.md)
+
+在源码中HideThen只在UK2Node_BaseAsyncTask中判断，因此这个标签只作用于蓝图异步节点。
+
+## 测试代码：
+
+```cpp
+UCLASS(Blueprintable, BlueprintType,meta = (ExposedAsyncProxy = MyAsyncObject))
+class INSIDER_API UMyFunction_Async :public UCancellableAsyncAction
+{}
+
+UCLASS(Blueprintable, BlueprintType,meta = (ExposedAsyncProxy = MyAsyncObject,HideThen))
+class INSIDER_API UMyFunction_Async :public UCancellableAsyncAction
+{}
+```
+
+## 使用HideThen前后对比：
+
+![Untitled](Untitled.png)
+
+## 源码位置：
+
+```cpp
+void UK2Node_BaseAsyncTask::AllocateDefaultPins()
+{
+	bool bExposeProxy = false;
+	bool bHideThen = false;
+	FText ExposeProxyDisplayName;
+	for (const UStruct* TestStruct = ProxyClass; TestStruct; TestStruct = TestStruct->GetSuperStruct())
+	{
+		bExposeProxy |= TestStruct->HasMetaData(TEXT("ExposedAsyncProxy"));
+		bHideThen |= TestStruct->HasMetaData(TEXT("HideThen"));
+		if (ExposeProxyDisplayName.IsEmpty())
+		{
+			ExposeProxyDisplayName = TestStruct->GetMetaDataText(TEXT("ExposedAsyncProxy"));
+		}
+	}
+
+	if (!bHideThen)
+	{
+		CreatePin(EGPD_Output, UEdGraphSchema_K2::PC_Exec, UEdGraphSchema_K2::PN_Then);
+	}
+
+}
+```