USubsystem | Unreal Engine 4.27 Documentation

Unreal Engine C++ API Reference > Runtime > Engine > Subsystems

Inheritance Hierarchy

References


Module	Engine
Header	/Engine/Source/Runtime/Engine/Public/Subsystems/Subsystem.h
Include	#include "Subsystems/Subsystem.h"

Syntax

class USubsystem : public UObject

Remarks

Subsystems are auto instanced classes that share the lifetime of certain engine constructs

Currently supported Subsystem lifetimes are: Engine -> inherit UEngineSubsystem Editor -> inherit UEditorSubsystem GameInstance -> inherit UGameInstanceSubsystem World -> inherit UWorldSubsystem LocalPlayer -> inherit ULocalPlayerSubsystem

Normal Example: class UMySystem : public UGameInstanceSubsystem Which can be accessed by: UGameInstance* GameInstance = ...; UMySystem* MySystem = GameInstance->GetSubsystem();

or the following if you need protection from a null GameInstance UGameInstance* GameInstance = ...; UMyGameSubsystem* MySubsystem = UGameInstance::GetSubsystem(GameInstance);

You can get also define interfaces that can have multiple implementations. Interface Example : MySystemInterface With 2 concrete derivative classes: MyA : public MySystemInterface MyB : public MySystemInterface

Which can be accessed by: UGameInstance* GameInstance = ...; const TArray& MySubsystems = GameInstance->GetSubsystemArray();

Constructors

	Type	Name	Description
		USubsystem ()

Functions

Type	Name	Description
void	Deinitialize ()	Implement this for deinitialization of instances of the system
void	Initialize ( FSubsystemCollectionBase& Collection )	Implement this for initialization of instances of the system
bool	ShouldCreateSubsystem ( UObject* Outer )	Override to control if the Subsystem should be created at all.