Error, use of undefined type 'AWeapon' ?

Development Programming & Scripting C++
1

So, i keep getting this error whatever i try to Spawn my weapon class using the following




DWGameCharacter.cpp // ACharacter subclass
////////////////////////////////////
// Inventory / Default Inventory
void ADWGameCharacter::DefaultInventory()
{
				FActorSpawnParameters SpawnInfo;
				SpawnInfo.bNoCollisionFail = true;
				AWeapon* NewWeapon = GetWorld()->SpawnActor<AWeapon>(DefaultInvWeaponClasses[0], SpawnInfo);
				WeaponsInInventory.Add(NewWeapon);

}
2

In your CPP try including the header of the file you are trying to spawn.

#include “Weapon.h”

2 Likes
3

That did it thanks!

4

Actually scratch that, UE4 Crashes as soon it calls the function

I tried using the forward declarations tutorial from A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

So my ADWGameCharacter.h looks like


// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.
#pragma once


#include "DWGameCharacter.generated.h"

class AWeapon;

UCLASS(config=Game)
class ADWGameCharacter :  ACharacter
{
	GENERATED_UCLASS_BODY()

        AWeapon* CurrentWeapon
        // other non relevant vars
};

and the .cpp stays pretty much the same, yet when i try to compile i still get the error about using a undefined type, if i include the Weapon.h in my ADWGameCharacter.cpp i can compile fine but
The game crashes as soon DefaultInventory() is called

5

Without the call stack it is difficult to be sure, but most likely the GetWorld() call is returning NULL because you are calling that function at a time when the world cannot yet be determined.

6

Hehe Yeah i changed it to occur on BeginPlay and it doesnt crash anymore, So if i ever need to spawn / add another class i just include its header?

7

Yes, you need to include it’s header if you want to use it, not just spawn.

There may be a way of grouping all the game headers together into one file and just using that, but I’m not sure if that’s recommended. I know with my setup in the Beta build I didn’t seem to need to include all the headers and they were recognized, but I’ve had to add them all with the release.