U++ UE4官方文档课后作业

.h：

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

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "RotationAroundAc.generated.h"

UCLASS()
class FLOATINGCUBE_API ARotationAroundAc : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	ARotationAroundAc();

protected:
	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void Tick(float DeltaTime) override;
	UPROPERTY(EditAnywhere, BlueprintReadWrite)
		UStaticMeshComponent* Child1;

	UPROPERTY(EditAnywhere, BlueprintReadWrite)
		UStaticMeshComponent* Father;

	UPROPERTY(EditAnywhere, BlueprintReadWrite)
		class USpringArmComponent* CameraSpring;

	UPROPERTY(EditAnywhere, BlueprintReadWrite)
		int ZRotation;

	UPROPERTY(EditAnywhere, BlueprintReadWrite)
		int ZoomRotation;

	UFUNCTION(BlueprintCallable)
		void DestroyMyself();

	UPROPERTY(EditAnywhere, BlueprintReadWrite)
		float destroyTime;
};

.cpp：

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


#include "RotationAroundAc.h"
#include "Camera/CameraComponent.h"
#include "GameFramework/SpringArmComponent.h"
#include "GameFramework/Actor.h"
#include "CoreMinimal.h"
#include "Engine.h"

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

	Father = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("FatherAc"));
	CameraSpring = CreateDefaultSubobject<USpringArmComponent>(TEXT("Spring"));
	RootComponent = Father;
	CameraSpring->SetRelativeLocationAndRotation(FVector(0.0f, 0.0f, 0.0f), FRotator(-60.0f, 0.0f, 0.0f));
	Child1 = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("Child1"));
	Child1->SetupAttachment(CameraSpring, USpringArmComponent::SocketName);
	Child1->SetRelativeLocationAndRotation(FVector(0.0f, 0.0f, 0.0f), FRotator(0.0f, 0.0f, 0.0f));
	CameraSpring->TargetArmLength = 50.0f;
	CameraSpring->bEnableCameraLag = true;
	CameraSpring->CameraLagSpeed = 3.0f;
	CameraSpring->SetupAttachment(Father);
	ZRotation = 0;
	ZoomRotation = 10;
	destroyTime = 10.0f;
}

void ARotationAroundAc::DestroyMyself() {
	Child1->DestroyComponent();
	return;
}

// Called when the game starts or when spawned
void ARotationAroundAc::BeginPlay()
{
	Super::BeginPlay();
	FTimerHandle TimeHandle;
	GetWorld()->GetTimerManager().SetTimer(TimeHandle, this, &ARotationAroundAc::DestroyMyself, destroyTime, true);
}

// Called every frame
void ARotationAroundAc::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);
	ZRotation += ZoomRotation;
	CameraSpring->SetWorldRotation(FRotator(0.0f, ZRotation, 40.0f));
}