UE5 自定义蓝图节点（记录，备忘）

创建一个工程项目，创建一个K2Node类（生成节点），创建一个蓝图函数库（实现节点内功能）

项目.Build.cs内添加模块

// Copyright Epic Games, Inc. All Rights Reserved.

using UnrealBuildTool;

public class NewCoustNode : ModuleRules
{
	public NewCoustNode(ReadOnlyTargetRules Target) : base(Target)
	{
		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
	
		PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore" });

		PrivateDependencyModuleNames.AddRange(new string[] { "BlueprintGraph","UnrealEd","GraphEditor","KismetCompiler" });

		// Uncomment if you are using Slate UI
		// PrivateDependencyModuleNames.AddRange(new string[] { "Slate", "SlateCore" });
		
		// Uncomment if you are using online features
		// PrivateDependencyModuleNames.Add("OnlineSubsystem");

		// To include OnlineSubsystemSteam, add it to the plugins section in your uproject file with the Enabled attribute set to true
	}
}

K2Node.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "K2Node.h"
#include "MyNode.generated.h"

/**
 * 
 */
UCLASS()
class NEWCOUSTNODE_API UMyNode : public UK2Node
{
	GENERATED_BODY()

public:

	// //鼠标放到上面的说明/注释
	// virtual FText GetTooltipText()const override;
	// //节点名称
	// virtual FText GetNodeTitle(ENodeTitleType::Type TitleType)const override;
	// //将节点添加到蓝图视图
	// virtual void GetMenuActions(FBlueprintActionDatabaseRegistrar& ActionRegister)const override;
	// //蓝图节点的标签
	// virtual FText GetMenuCategory()const;
	// //展开节点
	// virtual void ExpandNode(FKismetCompilerContext& CompilerContext, UEdGraph* SourceGraph)override;
	// //分配默认引脚
	// virtual void AllocateDefaultPins()override;
	// //引脚更改时会调用
	// virtual void PinDefaultValueChanged(UEdGraphPin* ChangedPin)override;
	// //连接情况更改以后
	// virtual void NotifyPinConnectionListChanged(UEdGraphPin* Pin)override;
	//
	// //创建一个可视小部件来在图形编辑器或图形面板中表示这个节点。如果没有实现，则将使用默认的节点工厂
	// virtual TSharedPtr CreateVisualWidget() { return TSharedPtr(); }
	// // 为表示此节点的小部件创建背景图像
	// virtual TSharedPtr CreateNodeImage() const { return TSharedPtr(); }
	// //右键菜单, 比如添加RemovePin
	// virtual void GetNodeContextMenuActions(class UToolMenu* Menu, class UGraphNodeContextMenuContext* Context) const override;

	//鼠标放到上面的说明/注释
	virtual FText GetTooltipText() const override { return FText::FromString(TEXT("This node is used for everyone to learn")); }
	//节点名称
	virtual FText GetNodeTitle(ENodeTitleType::Type TitleType) const override { return FText::FromString(TEXT("My Node")); }
	//蓝图节点的标签
	virtual FText GetMenuCategory() const { return FText::FromString(TEXT("This is My ClassMenu")); }

	//重写UK2Node的GetMenuActions函数，使其可以在右键菜单里找到这个蓝图节点
	virtual void GetMenuActions(FBlueprintActionDatabaseRegistrar& ActionRegistrar) const override;
	//分配默认引脚
	virtual void AllocateDefaultPins() override;
	//节点调用函数
	virtual void ExpandNode(FKismetCompilerContext& CompilerContext, UEdGraph* SourceGraph)override;
	
};

K2Node.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "NewCoustNode/Public/MyNode.h"

#include "BlueprintActionDatabaseRegistrar.h"
#include "BlueprintNodeSpawner.h"
#include "K2Node_CallFunction.h"
#include "KismetCompiler.h"
#include "MyBlueprintFunctionLibrary.h"

//通用，可以固定格式
void UMyNode::GetMenuActions(FBlueprintActionDatabaseRegistrar& ActionRegistrar) const
{
	Super::GetMenuActions(ActionRegistrar);

	UClass* ActionKey = GetClass();
	//ActionRegistrar需要include
	if (ActionRegistrar.IsOpenForRegistration(ActionKey))
	{
		//UBlueprintNodeSpawner需要include
		UBlueprintNodeSpawner* NodeSpawner = UBlueprintNodeSpawner::Create(GetClass());
		check(NodeSpawner != nullptr);

		ActionRegistrar.AddBlueprintAction(ActionKey, NodeSpawner);
	}
}

void UMyNode::AllocateDefaultPins()
{
	Super::AllocateDefaultPins();

	//创建输入引脚
	CreatePin(EGPD_Input, UEdGraphSchema_K2::PC_Exec, UEdGraphSchema_K2::PN_Execute);

	//创建输出引脚01
	UEdGraphPin* staring = CreatePin(EGPD_Output, UEdGraphSchema_K2::PC_Exec, UEdGraphSchema_K2::PN_Then);
	staring->PinFriendlyName = FText::FromString("staring");

	//创建输出引脚02
	UEdGraphPin* Finished = CreatePin(EGPD_Output, UEdGraphSchema_K2::PC_Exec, UEdGraphSchema_K2::PN_Then);
	Finished->PinFriendlyName = FText::FromString("finished");
}

void UMyNode::ExpandNode(FKismetCompilerContext& CompilerContext, UEdGraph* SourceGraph)
{
	Super::ExpandNode(CompilerContext, SourceGraph);

	UEdGraphPin* ExecPin = GetExecPin();
	UEdGraphPin* ThenPin = GetThenPin();
	if (ExecPin && ThenPin) {

		// 调用一个BlueprintFunctionLibrary节点,需要include "UMyBlueprintFunctionLibrary"
		FName MyFunctionName = GET_FUNCTION_NAME_CHECKED(UMyBlueprintFunctionLibrary, starting);

		//UK2Node_CallFunction需要include,CompilerContext需要include并且模块内要添加"BlueprintGraph","UnrealEd","GraphEditor","KismetCompiler"
		UK2Node_CallFunction* CallFuncNode = CompilerContext.SpawnIntermediateNode(this,SourceGraph);
		CallFuncNode->FunctionReference.SetExternalMember(MyFunctionName, UMyBlueprintFunctionLibrary::StaticClass());
		CallFuncNode->AllocateDefaultPins();
		CompilerContext.MovePinLinksToIntermediate(*ExecPin, *(CallFuncNode->GetExecPin()));


		FName MyFunctionName01 = GET_FUNCTION_NAME_CHECKED(UMyBlueprintFunctionLibrary, Finished);

		UK2Node_CallFunction* CallFuncNode01 = CompilerContext.SpawnIntermediateNode(this,SourceGraph);
		CallFuncNode01->FunctionReference.SetExternalMember(MyFunctionName01, UMyBlueprintFunctionLibrary::StaticClass());
		CallFuncNode01->AllocateDefaultPins();
		CompilerContext.MovePinLinksToIntermediate(*ExecPin, *(CallFuncNode01->GetExecPin()));
		
		// move pins
		CompilerContext.MovePinLinksToIntermediate(*ThenPin, *(CallFuncNode->GetThenPin()));
		CompilerContext.MovePinLinksToIntermediate(*ThenPin, *(CallFuncNode01->GetThenPin()));
	}
}

BlueprintFunctionLibrary.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "MyBlueprintFunctionLibrary.generated.h"

/**
 * 
 */
UCLASS()
class NEWCOUSTNODE_API UMyBlueprintFunctionLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()

public:
	UFUNCTION(BlueprintCallable, meta = (BlueprintInternalUseOnly = "true"))
	static void starting();

	UFUNCTION(BlueprintCallable, meta = (BlueprintInternalUseOnly = "true"))
	static  void Finished();
};

BlueprintFunctionLibrary.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "MyBlueprintFunctionLibrary.h"

void UMyBlueprintFunctionLibrary::starting()
{
	if (GEngine) {
		const int32 AlwaysAddKey = -1;

		GEngine->AddOnScreenDebugMessage(AlwaysAddKey,
			5.0f,
			FColor::Purple,
			TEXT("starting...")
		);
	}
}

void UMyBlueprintFunctionLibrary::Finished()
{
	if (GEngine) {
		const int32 AlwaysAddKey = -1;

		GEngine->AddOnScreenDebugMessage(AlwaysAddKey,
			5.0f,
			FColor::Red,
			TEXT("finished...")
		);
	}
}

这是简单定制蓝图节点的实现过程