c++ - ue4 c++ fps教程第3.2节出错，我该怎么办？

Question

我已经完成了关于虚幻引擎 4 的 fps 教程的第 3.2 节。在本节中，我应该通过 fire 函数实现对代码的射击，以便我可以在游戏中射击射弹。但是，在输入教程提供的代码后，我在编译时遇到了一个错误。错误如下

/Users/apple/Documents/Unreal Projects/FPSProject/Source/FPSProject/FPSCharacter.cpp:120:38：“Instigator”是“AActor”的私有成员

当我删除这一行并编译代码时，它会成功，但是当我在虚幻上测试它时，我根本无法发射弹丸。

这是代码

FPSCharacter.cpp

include "FPSCharacter.h"
include "FPSProject.h" #include "FPSCharacter.generated.h" #include "FPSProjectile.h" #include "GameFramework/Actor.h"

// Sets default values AFPSCharacter::AFPSCharacter() { // Set this character to call Tick() every frame. You can turn this off to improve performance if you don't need it. PrimaryActorTick.bCanEverTick = true;

 // Create a first person camera component.
 FPSCameraComponent = CreateDefaultSubobject<UCameraComponent>(TEXT("FirstPersonCamera"));
 // Attach the camera component to our capsule component.
 FPSCameraComponent->SetupAttachment(GetCapsuleComponent());
 // Position the camera slightly above the eyes.
 FPSCameraComponent->SetRelativeLocation(FVector(0.0f, 0.0f, 50.0f + BaseEyeHeight));
 // Allow the pawn to control camera rotation.
 FPSCameraComponent->bUsePawnControlRotation = true;

 // Create a first person mesh component for the owning player.
 FPSMesh = CreateDefaultSubobject<USkeletalMeshComponent>(TEXT("FirstPersonMesh"));
 // Only the owning player sees this mesh.
 FPSMesh->SetOnlyOwnerSee(true);
 // Attach the FPS mesh to the FPS camera.
 FPSMesh->SetupAttachment(FPSCameraComponent);
 // Disable some environmental shadowing to preserve the illusion of having a single mesh.
 FPSMesh->bCastDynamicShadow = false;
 FPSMesh->CastShadow = false;

 // The owning player doesn't see the regular (third-person) body mesh.
 GetMesh()->SetOwnerNoSee(true);
}

// Called when the game starts or when spawned void AFPSCharacter::BeginPlay() { Super::BeginPlay();

 if (GEngine)
 {
     // Put up a debug message for five seconds. The -1 "Key" value (first argument) indicates that we will never need to update or refresh this message.
     GEngine->AddOnScreenDebugMessage(-1, 5.0f, FColor::Red, TEXT("We are using FPSCharacter."));
 }
}

// Called every frame void AFPSCharacter::Tick( float DeltaTime ) { Super::Tick( DeltaTime );

}

// Called to bind functionality to input void AFPSCharacter::SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent) { Super::SetupPlayerInputComponent(PlayerInputComponent);

 // Set up "movement" bindings.
 PlayerInputComponent->BindAxis("MoveForward", this, &AFPSCharacter::MoveForward);
 PlayerInputComponent->BindAxis("MoveRight", this, &AFPSCharacter::MoveRight);

 // Set up "look" bindings.
 PlayerInputComponent->BindAxis("Turn", this, &AFPSCharacter::AddControllerYawInput);
 PlayerInputComponent->BindAxis("LookUp", this, &AFPSCharacter::AddControllerPitchInput);

 // Set up "action" bindings.
 PlayerInputComponent->BindAction("Jump", IE_Pressed, this, &AFPSCharacter::StartJump);
 PlayerInputComponent->BindAction("Jump", IE_Released, this, &AFPSCharacter::StopJump);
 PlayerInputComponent->BindAction("Fire", IE_Pressed, this, &AFPSCharacter::Fire);
}

void AFPSCharacter::MoveForward(float Value) { // Find out which way is "forward" and record that the player wants to move that way. FVector Direction = FRotationMatrix(Controller->GetControlRotation()).GetScaledAxis(EAxis::X); AddMovementInput(Direction, Value); }

void AFPSCharacter::MoveRight(float Value) { // Find out which way is "right" and record that the player wants to move that way. FVector Direction = FRotationMatrix(Controller->GetControlRotation()).GetScaledAxis(EAxis::Y); AddMovementInput(Direction, Value); }

void AFPSCharacter::StartJump() { bPressedJump = true; }

void AFPSCharacter::StopJump() { bPressedJump = false; }

void AFPSCharacter::Fire() { // Attempt to fire a projectile. if (ProjectileClass) { // Get the camera transform. FVector CameraLocation; FRotator CameraRotation; GetActorEyesViewPoint(CameraLocation, CameraRotation);

     // Transform MuzzleOffset from camera space to world space.
     FVector MuzzleLocation = CameraLocation + FTransform(CameraRotation).TransformVector(MuzzleOffset);
     FRotator MuzzleRotation = CameraRotation;
     // Skew the aim to be slightly upwards.
     MuzzleRotation.Pitch += 10.0f;
     UWorld* World = GetWorld();
     if (World)
     {
         FActorSpawnParameters SpawnParams;
         SpawnParams.Owner = this;
         SpawnParams.Instigator = Instigator;
         // Spawn the projectile at the muzzle.
         AFPSProjectile* Projectile = World->SpawnActor<AFPSProjectile>(ProjectileClass, MuzzleLocation, MuzzleRotation, SpawnParams);
         if (Projectile)
         {
             // Set the projectile's initial trajectory.
             FVector LaunchDirection = MuzzleRotation.Vector();
             Projectile->FireInDirection(LaunchDirection);
         }
     }
 }

}

标签： c++classcompiler-errorssyntax-errorunreal-engine4