Binding Enhanced Input Actions from C++

1. Set references to your Input Action and Input Mapping Context
2. Get Enhanced Input Component
3. Use BindAction to bind actions to functions
4. Register Input mapping context

//header
UPROPERTY(EditAnywhere, meta=(DisplayThumbnail=false))
UInputAction* MyAction;
 
UPROPERTY(EditAnywhere, meta=(DisplayThumbnail=false))
UInputMappingContext* InputMappingContext;
 
//cpp
void AMyCharacter::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)
{
	if(UEnhancedInputComponent* EnhancedInputComponent = Cast<UEnhancedInputComponent>(PlayerInputComponent))
	{
		EnhancedInputComponent->BindAction(JumpAction, ETriggerEvent::Started, this, &ACharacter::Jump);
		EnhancedInputComponent->BindAction(JumpAction, ETriggerEvent::Completed, this, &ACharacter::StopJumping);
 
		EnhancedInputComponent->BindAction(MoveAction, ETriggerEvent::Triggered, this, &ThisClass::HandleMoveInput);
		EnhancedInputComponent->BindAction(LookAction, ETriggerEvent::Triggered, this, &ThisClass::HandleLookInput);
 
		//etc
	}
}
 
void AMyCharacter::BeginPlay()
{
	Super::BeginPlay();
	
	if(APlayerController* PlayerController = Cast<APlayerController>(Controller))
	{
		if(UEnhancedInputLocalPlayerSubsystem* Subsystem = ULocalPlayer::GetSubsystem<UEnhancedInputLocalPlayerSubsystem>(PlayerController->GetLocalPlayer()))
		{
			Subsystem->AddMappingContext(InputMappingContext, 0);
		}
	}
}

(You need to assign values for the input actions and mapping context in a blueprint child class)

Gotchas §

BindAction does not hold a hard reference to the Input Action. This means if you don’t have a ref to the input action, it may get garbage collected, leading to your inputs no longer being handled.

This could occur for example if you load your input action from a Soft Object Pointer.

The fix is to store hard pointers to your input actions in a UPROPERTY.