11.软引用，同步，异步加载资源

引用和软引用

什么是软引用

 软引用的使用

        创建Actor，命名为MySoftActor

        软引用的声明

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "SoftPath")
	FSoftObjectPath softObjPath;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "SoftPath")
	FSoftClassPath softClsPath;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "SoftPath")
	TSoftObjectPtr<AActor> softObjPtr;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "SoftPath")
	TSoftClassPtr<AActor> softClsPtr;

声明完之后，进行编译，并生成蓝图，蓝图类，以及实例中就增加了对应属性

 异步加载和同步加载

 加入头文件,并在Actor的BeginPlay方法中实现同步和异步加载

#include "Engine/AssetManager.h"

void AMySoftActor::BeginPlay()
{
	Super::BeginPlay();
	softObjPath = TEXT("/Script/Engine.Texture2D'/Game/StarterContent/Textures/T_Brick_Clay_Beveled_M.T_Brick_Clay_Beveled_M'");
	//同步加载
	TSharedPtr<FStreamableHandle> SyncStreambleHandle = UAssetManager::GetStreamableManager().RequestSyncLoad(softObjPath);
	
	if (SyncStreambleHandle) {
		UTexture2D* image = Cast<UTexture2D>(SyncStreambleHandle->GetLoadedAsset());
		if (image) {
			GEngine->AddOnScreenDebugMessage(-1,5.0f,FColor::Red,FString::Printf(TEXT("image name is %s"), *image->GetName()));
		}
	}
	//异步加载
	FString Path = TEXT("/Script/Engine.Blueprint'/Game/StarterContent/Blueprints/Blueprint_CeilingLight.Blueprint_CeilingLight_C'");
	softClsPath = Path;
	TSharedPtr<FStreamableHandle> ASyncstreambleHandle = UAssetManager::GetStreamableManager().RequestAsyncLoad(softClsPath);
	if (ASyncstreambleHandle) {
		AActor *actor = Cast<AActor>(ASyncstreambleHandle->GetLoadedAsset());
		if (actor) {
			GEngine->AddOnScreenDebugMessage(-1, 5.0f, FColor::Red, FString::Printf(TEXT("actor name is %s"), *actor->GetName()));
		}
		else {
			GEngine->AddOnScreenDebugMessage(-1, 5.0f, FColor::Red, FString::Printf(TEXT("actor load error!")));
		}
		
	}
}