[游戏开发]UE4 C++ 的SpawnActor

UE4 C++ 的SpawnActor

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

#pragma once

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

UCLASS()
class GETSTARTED_API ASpwanVolume : public AActor
{
	GENERATED_BODY()

public:
	// Sets default values for this actor's properties
	ASpwanVolume();

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly)
	class UBoxComponent* SpawnBox; //碰撞盒子

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Spawn Volume")
	TArray<TSubclassOf<AActor>> SpawnActorClassesArray;//TSubclassOf 一个模板类

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

public:	
	// Called every frame
	virtual void Tick(float DeltaTime) override;

	UFUNCTION(BlueprintPure, Category = "Spawn Volume")
	FVector GetSpawnPoint();

	UFUNCTION(BlueprintPure, Category = "Spawn Volume")
	TSubclassOf<AActor> GetSpwnActorClass();


	UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category = "Spawn Volume")//有了BlueprintNativeEvent后我们的反射系统就会创建出两个东西
	void SpawnActor(UClass* SpawnClass,FVector SpawnLocation);

};

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


#include "Gameplay/SpwanVolume.h"
#include "Components/BoxComponent.h"
#include "Kismet/KismetMathLibrary.h"

// Sets default values
ASpwanVolume::ASpwanVolume()
{
 	// 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;

	SpawnBox = CreateDefaultSubobject<UBoxComponent>(TEXT("SpawnBox"));

	RootComponent = SpawnBox;//设置为跟组件

	

}

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

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

}

FVector ASpwanVolume::GetSpawnPoint()
{
	const FVector Origin = SpawnBox->GetComponentLocation();//获取位置
	const FVector Extent = SpawnBox->GetScaledBoxExtent();//盒子范围，按组件比例缩放。就是说放到场景后再放大，获取放大的范围
	
	return UKismetMathLibrary::RandomPointInBoundingBox(Origin, Extent); //使用第一个向量作为原点，将第二个向量作为框范围，返回指定边界框中的随机点。
}

TSubclassOf<AActor> ASpwanVolume::GetSpwnActorClass()
{
	if (SpawnActorClassesArray.Num() > 0) {//判断集合里有没有对象
		int index = FMath::RandRange(0, SpawnActorClassesArray.Num() - 1);
		return SpawnActorClassesArray[index];
	}
	else {
		return	nullptr;
	}
}

void ASpwanVolume::SpawnActor_Implementation(UClass* SpawnClass, FVector SpawnLocation)//这个就像是SpawnActor的父类的版本
{
	if (SpawnClass) {
		GetWorld()->SpawnActor<AActor>(SpawnClass, SpawnLocation, FRotator(0.0f));
	}

}

用蓝图调用C++写好的代码

给公开的变量集合赋值

运行后：