MenuInterface hides class member

[crash987]

I know that there is a closed thread about this, but i am unable to understand how to fix it. i have downloaded the file from github, i have copied the text from online and pasted it into visual studio 2019 (v 4.8.03752)and all times i get the C4458 error.

void UMainMenu::SetMenuInterface(IMenuInterface* MenuInterface)
{
    this->MenuInterface = MenuInterface;
}

void UMainMenu::HostServer()
{
    UE_LOG(LogTemp, Warning, TEXT("Host Button clicked"));
    if (MenuInterface != nullptr)
    {
        MenuInterface->Host();
    }
}

I have tried renaming all the MenuInterface pointers (links) to AMenuInterface and it builds but nothing happens

void UMainMenu::SetMenuInterface(IMenuInterface* MenuInterface)
{
    this->AMenuInterface = MenuInterface;
}

void UMainMenu::HostServer()
{
    UE_LOG(LogTemp, Warning, TEXT("Host Button clicked"));
    if (AMenuInterface != nullptr)
    {
        AMenuInterface->Host();
    }
}

Any kind of help would be great, even if it is just remake this point of the video for future people

Thanks

[sampattuzzi]

Seems like you are probably getting a compilation warning and that is not the actual issue. Could you give us a bit more context to what you are expecting and what isn’t happening?

[crash987]

If I have the code like what is in the video and save it in VS. When ue4 starts up, the app crashes on startup and the only way I have been able to fix it is by having the code like in the second code layout.

That’s what I am finding let’s VS compile and for ue4 to start up and run the game. Will be happy to upload a copy of both files (one that crashes ue4 and one that dosent crash ue4) to make looking into the problem easy

[Kobro]

Hey @crash987,
I stumbled upon the same problem you had and I am not quite sure why this is happening, hopefully with some extra context @sampattuzzi can tell us what is going on here, as I am quite curious as to why this is happening.
I did however manage to fix it by naming the IMenuInterface* parameter to something else than the name of the local IMenuInterface* variable.

Some screenshots:
MainMenu.h:

MainMenu.cpp:

Original compiler error message:

Hope this helps!

[crash987]

This is what is stopping me from continuing doing the course, I am really loving it, just a shame there seems to be no or little help on fixing it. I think this part needs a rework so others don’t have the same problem

[Kobro]

Could you show me your MainMenu.h?

Also, this->AMenuInterface = MenuInterface; is not necessary as the parameter is not named the same as the local variable. So AMenuInterface = MenuInterface; should be fine.

[sampattuzzi]

Make sure to delete your binaries and intermediates folders to make sure the compilation is up-to-date.

[crash987]

Hi Sam, i have just tried your idea of deleting the binaries and intermediates folder for the project, still getting the same problem “Error C4458 declaration of ‘MenuInterface’ hides class member”.

Is there a workaround that would get this fixed

[crash987]

so i have changed the code to how @Kobro has his code and i still have the same problem. what i had added in to the if null checker is a uelog to say if the host button to the game was valid or not.

so i now know that when the host button is pressed, MenuInterface is not valid and will not proceed to the game. With my very limited knowledge of cpp (or any) programming, i am now needing to find out where in the code it is braking and not working

[Kobro]

When you load the menu in the game instance do you set the interface like this:

Because your warning leads me to believe the MenuInterface is not set.

[crash987]

I’ll have to have a look when I get home, from memory the code is all there but will have to have a second look

EDIT:
it looks like i was missing the set menu interface in the PuzzlePlatformGameInstance.cpp, sadly i am still having the same problem. I will post the code here of what i have and hope there is something easy that i have missed

MainMenu cpp

bool UMainMenu::Initialize()
{
    bool Success = Super::Initialize();
    if (!Success) return false;

    if (!ensure(Host != nullptr)) return false;
    Host->OnClicked.AddDynamic(this, &UMainMenu::HostServer);
    Join->OnClicked.AddDynamic(this, &UMainMenu::JoinServer);
   return true;
}

void UMainMenu::SetMenuInterface(IMenuInterface* MMenuInterface)
{
    MenuInterface = MenuInterface;
}

void UMainMenu::JoinServer()
{
    UE_LOG(LogTemp, Warning, TEXT("Joining a game"));

}

void UMainMenu::Setup()
{
    this->AddToViewport();
    
    UWorld* World = GetWorld();
    if (!ensure(World != nullptr)) return;

    APlayerController* PlayerController = World->GetFirstPlayerController(); //get player controller
    if (!ensure(PlayerController != nullptr)) return;
    
    FInputModeUIOnly InputModeDate; // create input function

    InputModeDate.SetWidgetToFocus(this->TakeWidget()); //make Menu focus
    InputModeDate.SetLockMouseToViewportBehavior(EMouseLockMode::DoNotLock); //bring mouse into menu

    PlayerController->SetInputMode(InputModeDate); //alow mouse inputs in menu
    PlayerController->bShowMouseCursor = true; //show mouse in menu
}

void UMainMenu::TearDown()
{
    this->RemoveFromViewport();

    UWorld* World = GetWorld();
    if (!ensure(World != nullptr)) return;

    APlayerController* PlayerController = World->GetFirstPlayerController(); //get player controller
    if (!ensure(PlayerController != nullptr)) return;
    FInputModeGameOnly InputModeData;
    PlayerController->SetInputMode(InputModeData);
    PlayerController->bShowMouseCursor = false; //don't show mouse in menu
}

void UMainMenu::HostServer()
{
    UE_LOG(LogTemp, Warning, TEXT("Host Button clicked"));
    if (MenuInterface != nullptr)
    {
        UE_LOG(LogTemp, Warning, TEXT("MenuInterface is valid"));
        MenuInterface->Host();
    }
    else
    {
        UE_LOG(LogTemp, Warning, TEXT("MenuInterface is not valid"));
    }
}

MainMenu h

#include "CoreMinimal.h"
#include "Blueprint/UserWidget.h"
#include "MenuInterface.h"
#include "Engine/World.h"
#include "MainMenu.generated.h"

/**
 * 
 */
UCLASS()
class PUZZLEPLATFORMES_API UMainMenu : public UUserWidget
{
	GENERATED_BODY()

public:

	void SetMenuInterface(IMenuInterface* MMenuInterface);

	void Setup();

	void TearDown();

protected:
	virtual bool Initialize();


private:
	UPROPERTY(meta = (BindWidget))
	class UButton* Host;

	UPROPERTY(meta = (BindWidget))
	class UButton* Join;

	UFUNCTION()
	void HostServer();

	UFUNCTION()
	void JoinServer();

	IMenuInterface* MenuInterface = nullptr;
	
};

PuzzlePlatformGameInstance cpp

#include "PuzzlePlatformGameInstance.h"
#include "UObject/ConstructorHelpers.h"
#include "MenuSystem/MainMenu.h"

#include "Engine/Engine.h"
#include "Blueprint/UserWidget.h"
#include "PlatformTrigger.h"

UPuzzlePlatformGameInstance::UPuzzlePlatformGameInstance(const  FObjectInitializer& FObjectInitializer)
{
	ConstructorHelpers::FClassFinder<UUserWidget> MenuBPClass(TEXT("/Game/Menu_System/WBP_MainMenu")); //reading BluePrint from UE4
	if (!ensure(MenuBPClass.Class != nullptr)) return;
	MenuClass = MenuBPClass.Class;
}

void UPuzzlePlatformGameInstance::Init()
{
	UE_LOG(LogTemp, Warning, TEXT("Found class %s"), *MenuClass->GetName());

}

void UPuzzlePlatformGameInstance::LoadMenu()
{
	if (!ensure(MenuClass != nullptr)) return;
	Menu = CreateWidget<UMainMenu>(this, MenuClass);
	if (!ensure(Menu != nullptr)) return;
	
	Menu->Setup();
	Menu->SetMenuInterface(this);
}

void UPuzzlePlatformGameInstance::Host()
{
	if (Menu != nullptr)
	{
		Menu->TearDown();
	}

	UEngine* Engine = GetEngine();
	if (!ensure(Engine != nullptr)) return;

	Engine->AddOnScreenDebugMessage(0, 3, FColor::Red, TEXT("Hosting"));
	
	UWorld* World = GetWorld();
	if (!ensure(World != nullptr)) return;

	World->ServerTravel("/Game/ThirdPersonCPP/Maps/ThirdPersonExampleMap?listen"); //server levle travel

}

void UPuzzlePlatformGameInstance::Join(const FString& Address)
{
	UEngine* Engine = GetEngine();
	if (!ensure(Engine != nullptr)) return;

	Engine->AddOnScreenDebugMessage(0, 5, FColor::Green, FString::Printf(TEXT("Joining %s "), *Address));
	// client levle travel
	APlayerController* PlayerController = GetFirstLocalPlayerController();
	if (!ensure(PlayerController != nullptr)) return;

	PlayerController->ClientTravel(Address, ETravelType::TRAVEL_Absolute);
	

}

[Kobro]

In MainMenu.cpp:

void UMainMenu::SetMenuInterface(IMenuInterface* MMenuInterface)
{
    MenuInterface = MenuInterface;
}

Should be

void UMainMenu::SetMenuInterface(IMenuInterface* MMenuInterface)
{
MenuInterface = MMenuInterface;
}

Otherwise you are setting the variable to itself

[crash987]

Big thanks for that. i thought i had changed the MenuInterface = MMenuInterface to that. I suppose it’s a good idea to always have a second set of eyes to help with other peoples code, and to also not code when your tired.

Again big thanks @Kobro for your help