写在前面 

       PrimaryActorTick.bCanEverTick这个赋值为true也好，false也好，好像只能在构造函数里面起作用，应该就是当在构造函数里面执行

PrimaryActorTick.bCanEverTick = true;

之后，UE会在BeginPlay阶段自动执行

PrimaryActorTick.RegisterTickFunction(GetLevel());

就是自动注册了Tick方法。

        Tick注销的办法是

PrimaryActorTick.UnRegisterTickFunction();

        做了一段Actor自动上升的控制，通过计时器不断将Tick方法进行注册和注销，让Actor一会上升，一会儿停止。

启用和停用Tick的代码示例

.h文件代码：

#pragma once#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "DrawLine3D.generated.h"UCLASS()
class LEARNINGBP00_API ADrawLine3D : public AActor
{GENERATED_BODY()private:UStaticMesh* SM_Knot;UMaterial* matA;UStaticMeshComponent* StaticMeshA;public:	ADrawLine3D();protected:virtual void BeginPlay() override;public:virtual void Tick(float DeltaTime) override;FTimerHandle timeHandleA;FTimerHandle timeHandleB;//注册Tick的方法void RegisterTick();//注销Tick的方法void UnRegisterTick();
};

.cpp文件代码：

#include "DrawLine3D.h"ADrawLine3D::ADrawLine3D()
{SM_Knot = Cast<UStaticMesh>(StaticLoadObject(UStaticMesh::StaticClass(), NULL, TEXT("/Game/FBX/Knot")));matA = Cast<UMaterial>(StaticLoadObject(UMaterial::StaticClass(), NULL, TEXT("/Game/Material/MatA")));StaticMeshA = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("StaticMeshA"));StaticMeshA->SetStaticMesh(SM_Knot);StaticMeshA->SetMaterial(0, matA);PrimaryActorTick.bCanEverTick = true;//这个应该是只能在构造函数里面起作用。
}void ADrawLine3D::BeginPlay()
{Super::BeginPlay();//通过定时器设置每隔6秒注销TickGetWorldTimerManager().SetTimer(timeHandleA, this, &ADrawLine3D::UnRegisterTick, 6, true, 2);//通过定时器设置每隔6秒注册TickGetWorldTimerManager().SetTimer(timeHandleB, this, &ADrawLine3D::RegisterTick, 6, true, 5);
}void ADrawLine3D::Tick(float DeltaTime)
{Super::Tick(DeltaTime);//Actor以每秒10个单位的速度上升AddActorLocalOffset(FVector(0, 0, 10 * DeltaTime));
}void ADrawLine3D::RegisterTick() 
{PrimaryActorTick.RegisterTickFunction(GetLevel());GEngine->AddOnScreenDebugMessage(-256, 2, FColor::Blue, FString("RegisterTick"));
}void ADrawLine3D::UnRegisterTick() 
{PrimaryActorTick.UnRegisterTickFunction();GEngine->AddOnScreenDebugMessage(-111, 2, FColor::Red, FString("UnRegisterTick"));
}