Data type in the header file is not referenced

[seungmki]

In my AActor derived class, I want to create a function that takes a FLiveLinkSubjectName as an argument.
According to the official documentation, LiveLinkTypes.h and ‘LiveLinkInterface’ module are required to use FLiveLinkSubjectName.
So I wrote the header file and .Build.cs file of my class as below.

#include "LiveLinkTypes.h"

UFUNCTION(BlueprintCallable, Category = "AnimBP Variable")
		void SetLiveLinkSubjectNameInAnimBP(UClass* AnimBP, FString VariableName, FLiveLinkSubjectName Data);


///////////////////////////////


public class Test0803 : ModuleRules
{
	public Test0803(ReadOnlyTargetRules Target) : base(Target)
	{
		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
	
		PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "LiveLink", "LiveLinkInterface", });

		PrivateDependencyModuleNames.AddRange(new string[] { });

		// 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
	}
}

I made sure the LiveLink plugin in my UE project was also turned on.

After compiling, I got an error (C2079, C2664) that FLiveLinkSubjectName is not recognized. How can I solve this problem? ;_;…

[seungmki]

Oh my gosh, I was wrong! I can see why it didn’t compile!
It was because I only declared the function in the header file and did not define the function in the cpp file!
UFUNCTION() wasn’t the cause, UFUNCTION() was a must-have on top of the function!

UFUNCTION(BlueprintCallable, Category = "AnimBP Variable")
void NeedToTest(struct FLiveLinkSubjectName Name); //Be sure to define the function in the cpp file.

I’m really sorry for the confusion. ㅠ_ㅠ

(The following is incorrect)
After some experimentation yesterday, I was able to include “LiveLinkTypes.h” in my cpp file and compile!
I also found the cause of the compilation failure. Functions with parameters of type FLiveLinkSubjectName cannot be compiled when exposed to Blueprints!

Even if I wrote the module as shown below and turned on the LiveLink module, it did not compile when I enabled the specifier commented in the code below.
I’m writing this in case there are people struggling like me!

//UFUNCTION(BlueprintCallable, Category = "AnimBP Variable")
void NeedToTest(struct FLiveLinkSubjectName Name);

////////////////

PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "LiveLink", "LiveLinkInterface", });

PrivateDependencyModuleNames.AddRange(new string[] {  });