UE4C++ AActor类的创建

创建一个带StaticMeshComponent的AActor类

MyActor.h

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

#pragma once

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

UCLASS() //因为Actor父类就已经是blueprintable ，所以不用在括号里面声明
class FIRSTDEMO_API AMyActor : public AActor
{
	GENERATED_BODY()

public:	
	// Sets default values for this actor's properties
	//构造函数
	AMyActor();

	//定义组件 VisibleAnywhere 任何地方可见
	UPROPERTY(VisibleAnywhere,Category="My Actor Components") //任何地方都可见
	UStaticMeshComponent* StaticMesh;  //组件名为  StaticMesh ,组件名为后面的指针名

	//EditInstanceOnly 只有在实例中才能修改
	UPROPERTY(EditInstanceOnly,Category="My Actor Properties | FVector")
	//物体初始化transform
	FVector InitLocation;

	//VisibleInstaceOnly 在实例中可见
	UPROPERTY(VisibleInstanceOnly, Category = "My Actor Properties | FVector")
	FVector PlacedLocation;

	//EditDefaultsOnly 只能在类默认值中编辑，实例化对象中看不到这个变量存在
	UPROPERTY(EditDefaultsOnly, Category = "My Actor Properties | FVector")
	bool bGotoInitLocation; //ue默认 bool变量前都要加上b
	//VisibleDefaultsOnly 默认可见
	UPROPERTY(VisibleDefaultsOnly, Category = "My Actor Properties | FVector")
	FVector WorldOrigin;
	//EditAnywhere 任何地方（类，实例）都可编辑                        //限制条件：限制UE中输入框中的最小值和最大值，ClampMin实际的对应UIMin，相应的
	UPROPERTY(EditAnywhere, Category = "My Actor Properties | FVector", meta = (ClampMin = -5.f, ClampMax = 5.f, UIMin = -5.f, UIMax = 5.f))
	FVector TickLocationOffset;

	UPROPERTY(EditAnywhere, Category = "My Actor Properties | FVector")
	bool bShouldMove;

	UPROPERTY(EditInstanceOnly, Category = "My Actor Properties | Physics")
	FVector InitForce;

	UPROPERTY(EditInstanceOnly, Category = "My Actor Properties | Physics")
	FVector InitTorque;

	UPROPERTY(EditInstanceOnly, Category = "My Actor Properties | Physics")
	bool bAccelChange;

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

public:	
	// Called every frame
	//event tick ,from parent class override
	virtual void Tick(float DeltaTime) override;
};

MyActor.cpp

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


#include "MyActor.h"
#include "Components/StaticMeshComponent.h"

// Sets default values
AMyActor::AMyActor()
{
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	//如果不需要eventtick 这个函数的话就可以设为 false，增加程序的性能
	PrimaryActorTick.bCanEverTick = true;

	//组件初始化
    //创建一个默认的子物体，后面传入的是一个模板，TEXT宏后面是一个ue封装好的一个FString类型   
	//模板函数，后面传入的是一个模板
	StaticMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("MyStaticMesh"));

	InitLocation = FVector(0.0f, 100.0f, 200.0f);
	PlacedLocation = FVector(0.0f);
	bGotoInitLocation = false;
	WorldOrigin = FVector(0.0f);
	TickLocationOffset = FVector(1.f);
	bShouldMove = false;

	InitForce = FVector(0.f);
	InitTorque = FVector(0.f);
	bAccelChange = false;
}

// Called when the game starts or when spawned
void AMyActor::BeginPlay()
{
	//调用父类的beginplay()
	Super::BeginPlay();
	PlacedLocation = GetActorLocation();
	if (bGotoInitLocation)
	{
		SetActorLocation(InitLocation);
	}
	StaticMesh->AddForce(InitForce,TEXT("NAME_None"),bAccelChange);
	StaticMesh->AddTorque(InitTorque, TEXT("NAME_None"), bAccelChange);

	//FMath::Lerp();
	//FMath::FRandRange();
}

// Called every frame
void AMyActor::Tick(float DeltaTime)
{
	//调用父类的eventtick()
	Super::Tick(DeltaTime);
	if (bShouldMove)
	{
		FHitResult HitResult;
		AddActorLocalOffset(TickLocationOffset,true,&HitResult);
		UE_LOG(LogTemp, Warning, TEXT("X: %.f, Y: %.f, Z: %.f"), HitResult.Location.X, HitResult.Location.Y, HitResult.Location.Z);
	}
}