problem make the login widget work

Development Programming & Scripting C++
1

i using this tuturial to make my login screen in c++
i using visual studio 2015 Comunity and Unreal Engine 4.15.2https://youtube.com/watch?v=1wY35cep5V4and i have this errors
Severity Code Description Project File Line Suppression State
Error (active) pointer to incomplete class type is not allowed FirstGame c:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp 41
Error C2275 ‘UUserWidget’: illegal use of this type as an expression FirstGame C:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp 40
Error C2027 use of undefined type ‘UUserWidget’ FirstGame C:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp 41
Error C2227 left of ‘->AddToViewport’ must point to class/struct/union/generic type FirstGame C:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp 41
Error (active) type name is not allowed FirstGame c:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp 40

my code


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

#pragma once

#include "Engine/GameInstance.h"
#include "StateManager.generated.h"

/*Unumeration class */
UENUM(BlueprintType)
enum class EGameState :uint8 {
	ENone			UMETA(DisplayName = "None"),
	EStartup		UMETA(DisplayName = "Start"),
	ELoginScreen	UMETA(DisplayName = "LoginScreen"),
};
/**
 * 
 */
UCLASS()
class FIRSTGAME_API UStateManager : public UGameInstance
{
	GENERATED_BODY()
	

public:

	UPROPERTY(EditDefaultsOnly, Category = "State Manager")
		TSubclassOf<class UUserWidget> cLoginMenu;
	
	virtual void Init() override;

	UFUNCTION(BlueprintCallable, Category = "State Manager")
		void ChangeState(EGameState newState);

	EGameState GetGameState();

private:

	UUserWidget *currentWidget;
	

	EGameState currentState;

	void EnterState(EGameState newState);
	void LeaveState(EGameState oldState);
};



Severity	Code	Description	Project	File	Line	Suppression State
Error	C2275	'UUserWidget': illegal use of this type as an expression	FirstGame	C:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp	40	
Error	C2027	use of undefined type 'UUserWidget'	FirstGame	C:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp	41	
Error	C2227	left of '->AddToViewport' must point to class/struct/union/generic type	FirstGame	C:\Users\Pedro\Documents\Unreal Projects\FirstGame\Source\FirstGame\StateManager.cpp	41
2

You need to add the UserWidget.h header file to your .cpp file.

You also probably need to include the “UMG”, “Slate” and “SlateCore” dependencies to your projects build.cs file.

3

thanks
for the help its work
Have a good day , night or afternoon
Have a good weekend

4

how i change umg for another by widget when i click in button code
i using this tutorial to make my login system 02 - [C++] GameSparks in Unreal Engine - Building the Login System (1/2) - YouTube

void ULoginMenuWidget::OnOptionsClicked()
{

if (GetWorld()-&gt;GetGameInstance())
{
	UStateManager *StateManager = Cast&lt;UStateManager&gt;(GetWorld()-&gt;GetGameInstance()); 
	if (StateManager) 
	{ StateManager-&gt;ChangeState(EGameState::EOptionsScreen);
	}
}
/*
if (GEngine) {
	GEngine-&gt;AddOnScreenDebugMessage(-1, 2.f, FColor::MakeRandomColor(), TEXT("Options"));
}
/**/

}
and i click in the options button my game crash