UE4 新手常用C++API

C++暴露给蓝图可编辑

UCLASS(Blueprintable)

创建FString

FString::Printf(TEXT("aa bb"));

蓝图调用变量

UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )

限制条件范围

meta = (ClampMin=0.1,ClampMax = 100)

蓝图识别组件

UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "XXX")

返回物理材质

EPhysicalSurface SurfaceType = UPhysicalMaterial::DetermineSurfaceType(Hit.PhysMaterial.Get());

开放给编辑器时的类型，而不是某一个引用

TSubClassOf

软引用

TSoftObjectPtr

TSoftClassPtr 

蓝图调用函数
UFUNCTION(BlueprintCallable, Category = "XXX")

强制GC

GEngine->ForceGarbageCollection(true);

设置子Actor

HandObject->SetChildActorClass(ASlAiHandObject::StaticClass());

继承父类
Super::Xxx();  

物体投射阴影

void UPrimitiveComponent::SetCastShadow(bool NewCastShadow)

获取组件

GetComponentByClass(UXXXComponent::StaticClass());

输入参数为UWorld（const UObject* WorldContextObject）时

UWorld* World = GEngine->GetWorldFromContextObject(WorldContextObject, EGetWorldErrorMode::LogAndReturnNull);
    if (World == nullptr)
        return nullptr;

调整Tick间隔为1秒

PrimaryActorTick.TickInterval = 1.0f;

循环输出ForEachLoop   FStringaa 

for(FString xx : FStringaa){}

设置鼠标点击输入模式（controlelr）

FInputModeGameOnly InputMode;
InputMode.SetConsumeCaptureMouseDown(true);
SetInputMode(InputMode);

碰撞体物理旋转锁定

BoxCollision->GetBodyInstance()->bLockZRotation = true;

本地化

NSLOCTEXT("namespace", "key", "value")

播放音效

UGameplayStatics::SpawnSoundAttached(soundcue,RootComponent);

向量长度

Fvector.size();

查找子widget

widgettree->FindName

Widget的初始化函数

public:
    virtual bool Initialize() override;

protected:
    Widget的tick函数
    virtual void NativeTick(const FGeometry& MyGeometry, float InDeltaTime) override;

    virtual void NativePreConstruct()override;
    virtual void NativeConstruct()override;

UPROPERTY(Meta = (BindWidget)) (绑定UMG中名字叫MyBtn的按钮)

UButton* MyBtn;

例：void BeginDestroy() override;

void AmyActor::BeginDestroy()
{
Super::BeginDestroy();
UE_LOG(LogTemp, Warning, TEXT("Game exit!"));

}

C++调用蓝图函数

首先创建C++为基类，蓝图继承后创建一个函数Test

#include "OutputDevice.h"

FString cmd = FString::Printf(TEXT("BB CD"));

//BB函数名，CD参数

FOutputDeviceDebug device;
CallFunctionByNameWithArguments(*cmd, device, NULL, true);

蓝图重载C++函数(可以在C++中其他位置调用一个目前没有任何功能的函数（事件），而该函数的具体实现交给蓝图实现)

UFUNCTION(BlueprintImplementableEvent)       

void OnTest(); 

在蓝图中Add Event，找到对应的函数名，创建后即可实现具体逻辑

然后也可以在自己的C++代码中调用该方法

void MyActor::OnPressed()
{
OnTest();
}

蓝图添加默认的C++实现（C++在调用了SomeFunction()的地方先调用SomeFunction_Implementation的实现，但如果在蓝图中定义了SomeFunction事件（即使后面不连接任何内容），则会忽略C++中SomeFunction_Implementation中的实现，只采用蓝图中的实现）

UFUNCTION(BlueprintNativeEvent, Category = "SomeCategory")

 void SomeFunction();

void AMyActor::SomeFunction_Implementation() 

{ 

UE_LOG(LogTemp, Warning, TEXT("Implenetaion in C++")); 

}

loadstreamlevel的百分比调用

GetAsyncLoadPercentage(PackageName)

获取控制器

UGameplayStatics::GetPlayerController(GWorld, 0)；(->GetWorld())

获取默认蓝图类

HUDClass = AXXXHUD::StaticClass();

获取项目名字

FApp::GetProjectName();

判断Actor是蓝图还是C++

Actor->GetClass.IsNative();

按键

GetWorld()->GetFirstPlayerController()->WasInputKeyJustPressed(Key)
GetWorld()->GetFirstPlayerController()->WasInputKeyJustReleased(Key) 

确保内容存在，否则中断代码

ensure(XX)

鼠标在屏幕中的位置

#include "Engine/GameEngine.h"
#include "Engine/Engine.h"

FVector2D MousePosition;

GEngine->GameViewport->GetMousePosition(MousePosition);

MousePosition=MousePosition/DPIScale;

判断当前游戏运行模式

GetWorld()->WorldType

失焦后声音还能播放

GConfig->GetFloat(TEXT("Audio"), TEXT("UnfocusedVolumeMultiplier"), UnfocusedVolumeMultiplier, GEngineIni);

或者在DefaultEngine.ini中添加

[Audio]

UnfocusedVolumeMultiplier=1.0

加载地图

UGameplayStatics::OpenLevel(GetWorld(), *mapName);

获取角色位置和方向

GetWorld()->GetFirstPlayerController()->GetPlayerViewPoint(PawnLocation,PawnRotation);//面朝的方向

当前帧

#include "Engine/World.h"

GetWorld()->DeltaTimeSeconds

当前旋转量

this->GetActorForwardVector().Rotation()

单位向量

PawnRotation.Vector();

PawnVector.GetSafeNormal();

获取速度

auto ForwardSpeed = FVector::DotProduct(MoveVelocityNormal, AIForwardNormal);

运行命令行
GetWorld()->GetFirstPlayerController()->ConsoleCommand("quit");
打印
GEngine->AddOnScreenDebugMessage(-1, 5.0f, FColor::Yellow, FString::Printf(TEXT("%s"),*FString));
#include "Misc/OutputDevice.h"
GLog->Logf(TEXT("%s"), *Filepath);

FMessageLog("MyLog").Warning(FText::FromString(TEXT("这是一条新的信息")));

限制函数

FMath::Clamp(A1 + A2, 0.0, 1.0);
设置位置
SetActorLocation(FVector(0.0f, 0.0f, 250.0f));

打开EXE

FString pathrul = FPaths::RootDir() + url;
    FPlatformProcess::CreateProc(*url, nullptr, true, false, false, nullptr, -1, nullptr, nullptr);

#include
#include
ShellExecute(NULL, NULL, (*pathrul), NULL, NULL, SW_SHOWDEFAULT);

添加到控制台函数

UFUNCTION(Exec, Category = "AActor")

覆盖Actor控制台函数

virtual bool ProcessConsoleExec(const TCHAR* Cmd, FOutputDevice& Ar, UObject* Executor) override;

bool UMyGameInstance::ProcessConsoleExec(const TCHAR* Cmd, FOutputDevice& Ar, UObject* Executor)
{
    bool Res = Super::ProcessConsoleExec(Cmd, Ar, Executor);
    if (!Res)
    {
        //获取场景对象方法一: 
        for (TActorIterator It(GetWorld()); It; ++It)
        {
            Res = It->ProcessConsoleExec(Cmd, Ar, Executor);
        }
        //获取场景对象方法二:
        /*TArray ActArray;
        UGameplayStatics::GetAllActorsOfClass(GetWorld(), AMyCharacter::StaticClass(), ActArray);
        for(AActor* Act : ActArray) Act->ProcessConsoleExec(Cmd, Ar, Executor);*/
    }
    return Res;
}

判断exe是那个端

ENetMode netMode = GetNetMode();

switch(netMode)

{

case NM_Standalone :

print 单独端, 单机游戏

NM_DedicatedServer 专用服务器

NM_ListenServer 监听服务器

NM_Client 客户端

NM_MAX

}

MD5加密

FMD5::HashAnsiString(TEXT("someStuff"));

加载完地图回调

void UMyGameInstance::Init()
{
	Super::Init();

	//FCoreUObjectDelegates::PreLoadMap.AddUObject(this, &UMyGameInstance::BeginLoadingScreen);
	FCoreUObjectDelegates::PostLoadMapWithWorld.AddUObject(this, &UMyGameInstance::EndLoadingScreen);
}

void UMyGameInstance::EndLoadingScreen(UWorld* InLoadedWorld)
{
	UE_LOG(LogTemp, Warning, TEXT("END23131312"));
}

hashi加密

FString HashStringWithSHA1(const FString &InString)
{
FSHAHash StringHash;
FSHA1::HashBuffer(TCHAR_TO_ANSI(*InString), InString.Len(), StringHash.Hash);
return StringHash.ToString();
}

传一个Object蓝图
UPROPERTY(BlueprintReadWrite,EditAnywhere,Category = "XX")
TSubclassOfSkillBlueprintHelperObject;
路径

FString Str2 = FString::Printf(TEXT("Texture2D'/Game/pan/Frame_%05d.Frame_%05d'"),textName)
结构体
USTRUCT(Blueprintable)
struct MyStruct
{
GENERATED_USTRUCT_BODY()

//GENERATED_BODY()
public:
UPROPERTY(BlueprintReadWrite,EditAnywhere,Category = "XX")
int intCode;
UPROPERTY(BlueprintReadWrite,EditAnywhere,Category = "XX")
TMap Parameters;
};
创建结构体

FMyStruct* MyStruct = new FMyStruct();
查找场景中的Actor
AActor * AMyActor::FindActor(FString Actorname)
{
AActor* mActor = NULL;
if (GetWorld())
{
for (TActorIterator It(GetWorld()); It; ++It)
{
AActor* xActor = *It;
if (xActor->GetName() == Actorname)
{
GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, TEXT("Get it"));
mActor = xActor;
break;
}
}
if (!mActor)
{
GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, TEXT("No Get it"));
}
return  mActor;
}
else
{
GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, TEXT("NO getworld"));
return nullptr;
}

}

查找场景中的Actor2

#include "Kismet/GameplayStatics.h"

TArray PlayerStarts;
UGameplayStatics::GetAllActorsOfClass(GetWorld(), APlayerStart::StaticClass(), PlayerStarts);

if (PlayerStarts.Num() > 0)
    {
        APlayerStart* playerStart= Cast(PlayerStarts[0]);
    }

设置暂停

SetPause(true);

绑定按键（PS：需要在Pawn或Character里）
void AMyActor::SetupPlayerInputComponent(class UInputComponent* InputComponent)
{
InputComponent->BindKey(EKeys::Z, IE_Released, this, &AMyActor::OpenURL);
InputComponent->BindAction("Grow", IE_Released, this, &AMyActor::OpenURL);//.bExecuteWhenPaused = true;在暂停是依旧能运行
InputComponent->BindAxis("back", this, &AMyActor::OpenURL);
}
返回多个值，引用
void AMyActor::MoreReturn(FString& A, bool& B)
{

}

Udata->AddToRoot();//防止GC回收

Udata->RegisterWithGameInstance((UObject*)WorldContextObject);//防止GC回收

蓝图显示中文枚举类（VS文件-高级保存选项UTF-8格式）

UENUM(BlueprintType)

enum class EenumChinese :uint8 
{
E_EN UMETA(DisplayName = "英文"),  
E_CH UMETA(DisplayName = "中文"),  
};
UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "enumChinese")
EenumChinese enumChinese;


双选项枚举类
UENUM(BlueprintType)
enum class EMyEnum : uint8
{
BranchA,
BranchB,
};
UFUNCTION(BlueprintCallable, Category = "My|MyActor", Meta = (ExpandEnumAsExecs = "Branches"))
void BranchFun(int32 Input, EMyEnum& Branches);
void AMyActor::BranchFun(int32 Input, EMyEnum& Branches)
{
if (Input == 1)
{
Branches = EMyEnum::BranchA;
}
else
{
Branches = EMyEnum::BranchB;
}
}

循环迭代

for (TArray::TIterator It(MenuAudioResource.Find(FString("Sound"))->CreateIterator()); It; ++It)
        {
            (*It)->VolumeMultiplier = SoundVolume;
        }

迭代controller

for (FConstPlayerControllerIterator It = GetWorld()->GetPlayerControllerIterator(); It; It++){AXXPlayerController* PC = Cast(It->Get());}
LOG
UE_LOG(LogTemp, Warning, TEXT("Info= %s"), *t_str[i]);
DEFINE_LOG_CATEGORY(LogMySlate);
UE_LOG(LogMySlate, Warning, TEXT("Found UObject named"));

蓝图打印

#include"MessageLog.h"

FMessageLog("DebugLog_FMessageLog").Warning(FText::FromString(MyString));
生成类
TestObjectActor = GWorld->SpawnActor(TestBlueprint);
UWorld* const World = GetWorld();
AActor* GridCube = World->SpawnActor(GridCubeClass2, FVector(0.0f, 90.0f, 50.0f), FRotator(0.0f, 0.0f, 0.0f));
读取Texture2D
UTexture2D* texture22 = Cast(StaticLoadObject(UTexture2D::StaticClass(), NULL, *(Path)));
获得名字

Actor->GetName() == TEXT("FloatActor_1")

获取相机

GetWorld()->GetFirstPlayerController()->PlayerCameraManager

强制转换
PTGameInstance = Cast(World->GetGameInstance());

设置碰撞类型
SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);

设置碰撞属性

SetCollisionProfileName(FName("NoCollision"));

设置碰撞属性
MeshFirst->SetCollisionObjectType(ECC_Pawn);
MeshFirst->SetCollisionEnabled(ECollisionEnabled::NoCollision);
MeshFirst->SetCollisionResponseToAllChannels(ECR_Ignore);
构造函数添加组件

RootComponent = CreateDefaultSubobject(TEXT("Center"));

动态创建UObject
UMyObject*NewObj=NewObject();

动态创建Object

FMyObject*NewObj= new FMyObject();

查找类

UClass* ActorRef = FindObject(ANY_PACKAGE,*FString("AActor"));

找蓝图Actor

UClass* aa = LoadClass( NULL, TEXT( "Blueprint'/Game/UMG/MainMenu.MainMenu_C'" ) );    (蓝图动态资源加载)  
static ConstructorHelpers::FObjectFinder assetObject(TEXT("/Game/Maps/test.test_C")); (蓝图构造函数资源加载)
if (assetObject.Succeeded())
{
TestBlueprint = (UClass*)assetObject.Object->GeneratedClass;
}
找材质(UObject构造函数资源加载)
static ConstructorHelpers::FObjectFinder MaterialAsset(TEXT("/Game/Maps/MAT.MAT"));
if (MaterialAsset.Succeeded())
{
Material = (UMaterial*)MaterialAsset.Object;
}

(UObject动态资源加载)

LoadObject<>();

创建动态材质
UMaterialInstanceDynamic* MiniMapMatDynamic = UMaterialInstanceDynamic::Create(MiniMapMatInst, nullptr);

绑定材质属性
  MiniMapMatDynamic->SetTextureParameterValue(FName("MiniMapTex"), MiniMapRender);

组件附加

SphereComp->SetupAttachment(MeshComp);

等待销毁时从控制器移除角色控制

DetachFromControllerPendingDestroy();

设置角色生命周期

SetLifeSpan(10.0f);

获取音乐设备
AudioDevice = GEngine->GetMainAudioDevice();

推送混音器到设备
AudioDevice->PushSoundMixModifier(SlAiSoundMix);

使用混音器来设置
AudioDevice->SetSoundMixClassOverride(SlAiSoundMix, SlAiMusicClass, MusicVolume, 1.f, 0.2f, false);

编辑器改变UPROPERTY参数时调用的函数

#if WITH_EDITOR
    virtual void PostEditChangeProperty(struct FPropertyChangedEvent& PropertyChangedEvent) override;
#endif

#if WITH_EDITOR
void AMyCharacter::PostEditChangeProperty(struct FPropertyChangedEvent& PropertyChangedEvent)
{
    Super::PostEditChangeProperty(PropertyChangedEvent);
    if (PropertyChangedEvent.Property && PropertyChangedEvent.Property->GetFName() == GET_MEMBER_NAME_CHECKED(AMyCharacter, Mynum))
    {
        Mynum2+= 10;
    }
}
#endif

屏幕大小

GetWorld()->GetFirstPlayerController()->GetViewportSize(ViewportSizeX,ViewportSizeY);
重力
SetEnableGravity(false);

随机数

FRandomStream Stream;

//产生新的随机种子
Stream.GenerateNewSeed();

int RandIndex = Stream.RandRange(0, ResourcePath.Num() - 1);

删除AIController

DetachFromControllerPendingDestroy();

进入观察者模式

StartSpectatingOnly();

复制资源

UBehaviorTree* myBehaviorTree = DuplicateObject(object,NULL)

退出游戏

UKismetSystemLibrary::QuitGame(this, nullptr, EQuitPreference::Quit);

GEngine->Exec(GWorld, *FString("Exit"));

获取游戏时间

double MyTime = FPlatformTime::Seconds;

获取时间

FDateTime::Now().ToString();
链接URL
FString TheURL = "xxxxxxxx";
FPlatformProcess::LaunchURL(*TheURL, nullptr, nullptr);

创建UI   "Media", "MediaAssets"
 if (nullptr == MainMenuWidget)    
{        
UClass* aa = LoadClass( NULL, TEXT( "Blueprint'/Game/UMG/MainMenu.MainMenu_C'" ) );        
MainMenuWidget = CreateWidget( GetWorld()->GetFirstPlayerController(), aa );    
}    
MainMenuWidget->AddToViewport(); 
//http://blog.csdn.net/zilisen/article/details/77645500

OR：

UPROPERTY(EditAnywhere, Category = "AA")
        TSubclassOf HUDWidgetClass;

UMyHUDWidget* HUDWidget = CreateWidget(GetWorld(), HUDWidgetClass);

子弹函数

#include "Kismet/GameplayStatics.h"

UGameplayStatics::SuggestProjectileVelocity(
this,
FireVector,
StartLocation,
EndLocation,
Speed,
false,
0,
0,
ESuggestProjVelocityTraceOption::DoNotTrace

);

绘制射线

#include "DrawDebugHelpers.h"

DrawDebugLine(
GetWorld(),
StartLocation1,
EndLocation1,
FColor(255, 0, 0),
false,
0.0f,
0.0f,
10.0f

);

FCollisionQueryParams QueryParameter = FCollisionQueryParams("", false, GetOwner());
FHitResult HitResult;
GetWorld()->LineTraceSingleByChannel(
HitResult,
StartLocation2,
EndLocation2,
FCollisionObjectQueryParams(ECollisionChannel::ECC_PhysicsBody),
QueryParameter
)

游戏运行中开启作弊等命令

static int32 DebugWeaponDrawing = 0;
FAutoConsoleVariableRef CVARDebugWeaponDrawing(
    TEXT("COOP.DebugWeapons"), 
    DebugWeaponDrawing, 
    TEXT("Draw Debug Lines for Weapons"), 
    ECVF_Cheat);

if(DebugWeaponDrawing >0){...}

计时器

#include "TimerManager.h"

FTimerHandle CountdownTimerHandle;
GetWorldTimerManager().SetTimer(CountdownTimerHandle, this, &AMytestActor::AdvanceTimer, 1.0f, true);

FTimerDelegate timeDele ;//  定义调用的委托

timeDele.BindRaw(this,&xxx:ffff); //绑定函数到委托
GWorld->GetTimerManager().UnPauseTimer(mTimer); //唤醒   GetWorld()
float elapsed = GWorld->GetTimerManager().GetTimerElapsed(mTimer); //已逝时间
float elapsed = GWorld->GetTimerManager().GetTimerRemaining(mTimer); //剩余时间
bool isActive = GWorld->GetTimerManager().IsTimerActive(mTimer); //激活
bool isPaused = GWorld->GetTimerManager().IsTimerPaused(mTimer); //暂停
bool isExist = GWorld->GetTimerManager().TimerExists(mTimer); //存在

GetWorldTimerManager().ClearTimer(CountdownTimerHandle);//停止计时器

伤害

#include

UGameplayStatics::ApplyRadialDamage(
this,
ActorDamage,
GetActorLocation(),
Radius,
UDamageType::StaticClass(),
TArray()//友军
)

获取IP地址
需要在build.cs添加Sockets模块
#include "SocketSubsystem.h"
#include "IPAddress.h"
FString IpAddr("NONE");
  bool canBind = false;
  TSharedRef LocalIp = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->GetLocalHostAddr(*GLog, canBind);
  if (LocalIp->IsValid())
  {
IpAddr = LocalIp->ToString(false); //（如果想附加端口就写 ture）
}
return IpAddr;
添加标签
MyActor.Tags.AddUnique(TEXT("MyTag"));  
销毁物体
MyActor->Destroy();
MyActor->SetLifeSpan(1);//延迟1S
截图
FString UMyBlueprintFunctionLibrary::TakeScreenShoot(FString picName, bool bUnique /*= true*/)
{
FString inStr;
FString Filename;
FScreenshotRequest::RequestScreenshot(picName + ".png", false, bUnique);
FString ResultStr = FScreenshotRequest::GetFilename();
ResultStr = FPaths::GetBaseFilename(ResultStr, true);
return ResultStr + ".png";

}

void UMyBlueprintFunctionLibrary::Screenshot(const FString InFilename, bool bInShowUI)
{
FScreenshotRequest SR = FScreenshotRequest();
FString savelocation = FPaths::ConvertRelativePathToFull(FPaths::GameDir());
FString filename = savelocation + FString(TEXT("/Saved/Screenshotss/")) + InFilename + FString(TEXT(".png"));
SR.RequestScreenshot(filename, bInShowUI, false);
}

写入配置文件，有GEditorIni,GEditorProjectIni,GCompatIni,GlightmassIni,GScalabilityIni,GHardwareIni,GInputIni,GGameIni,GGameUserSettingsIni等(查找CoreGlobals.h)
写的数据会写到 YourGame\Saved\Config\Windows\Game.ini 中
    const FString WriteSection = "MyCustomSection";
    //String
    GConfig->SetString(
        *WriteSection,
        TEXT("key1"),
        TEXT("Hello world"),
        GGameIni
    );
    GConfig->Flush(false, GGameIni);
读取配置
if (!GConfig) return 0;
float ValueReceived ;
GConfig->GetFloat(
TEXT("MyCustomSection"),
TEXT("key1"),
ValueReceived,
GGameIni
);
return ValueReceived;

服务器：

判断是否在服务端运行

GetWorld()->IsServer()

网络更新频率

NetUpdateFrequency = 66.0f;

MinNetUpdateFrequency = 33.0f;

枚举字节化

TEnumAsByte AA;

让矢量服务器传输不用那么精确

FVector_NetQuantize   vectorr；

复制变量到服务器

UPROPERTY(Replicated)

在服务器上运行函数

UFUNCTION(Server, Reliable, WithValidation)//NetMulticast

void Server();

void XXX::ServerFire_Implementation(){}

bool XXX::ServerFire_Validate(){return true;}//完整性检查才用到

判断是否在服务器上运行（Actor是否主机）

Role == ROLE_Authority

判断是否在客户端上运行

Role < ROLE_Authority

服务器变量改了通知客户端调用函数

UPROPERTY(ReplicatedUsing=OnRep_GuardState)

UFUNCTION()
    void OnRep_GuardState();

             规则：所有的客户端  #include "Net/UnrealNetwork.h"
void XXX::GetLifetimeReplicatedProps(TArray< FLifetimeProperty > & OutLifetimeProps) const
{
    Super::GetLifetimeReplicatedProps(OutLifetimeProps);

    DOREPLIFETIME(XXX（AActor）, 变量);

//DOREPLIFETIME_CONDITION(XXX（AActor）, 变量,COND_SkipOwner);
}

Slate：

创建slate

TSharedPtr MenuHUDWidget;

ASlAiMenuHUD::ASlAiMenuHUD()
{
    if (GEngine && GEngine->GameViewport) {

        SAssignNew(MenuHUDWidget, SSlAiMenuHUDWidget);

        GEngine->GameViewport->AddViewportWidgetContent(SNew(SWeakWidget).PossiblyNullContent(MenuHUDWidget.ToSharedRef()));

    }
}

播放动画

MenuAnimation = FCurveSequence();
MenuCurve = MenuAnimation.AddCurve(StartDelay, AnimDuration, ECurveEaseFunction::QuadInOut);

MenuAnimation.Play(this->AsShared());

把图片导入ImageSlot

SOverlay::FOverlaySlot* ImageSlot;

.Expose(ImageSlot)

点击事件

.OnClicked(this, &XXX::OnClick)

添加嵌套UMG控件到Slate控件里

ChildSlot[umgWidget->TakeWidget()];

添加slate到游戏窗口

GEngine->GetWorldFromContextObject(this, EGetWorldErrorMode::LogAndReturnNull)->GetGameViewport()->AddViewportWidgetContent(slateWidget);

内嵌到Slate控件内

slateWidget->AddWidget(umgWidget);

设置锚点

.Anchors(FAnchors(0.f))

创建按钮

+ SOverlay::Slot()

[

SNew(SButton)

]

布局

.HAlign(HAlign_Left)
.VAlign(VAlign_Top)

创建外部调用Slate

TSharedPtr ZhCheckBox;//.h

SAssignNew(ZhCheckBox,SCheckBox)

获取TWeakPtr实例

TWeakPtr< Sxxx>  xxx;

xxx.pin();

转换为共享指针

makeshareable(XX);

获取声音资源文件

FSlateSound.GetResourceObject()

FGeometry里面保存了Widget位置大小等属性

在鼠标事件中获取鼠标相对widget的位置

MyGeometry.AbsoluteToLocal(MouseEvent.GetScreenSpacePosition());

获取DPI

UWidgetLayoutLibrary::GetViewportScale(GEngine->GameViewport);

获取Widget之间的相对位置

FVector2D StartPos = WidgetA.AbsoluteToLocal(WidgetB->GetCachedGeometry().AbsolutePosition);

获取资源

FSlateApplication::Get().

AI行为树：

黑板:

#include "BehaviorTree/Blackboard/BlackboardKeyType_Enum.h"
#include "BehaviorTree/Blackboard/BlackboardKeyType_Vector.h"
#include "BehaviorTree/Blackboard/BlackboardKeyType_Float.h"
#include "BehaviorTree/Blackboard/BlackboardKeyType_Object.h"
#include "BehaviorTree/Blackboard/BlackboardKeyType_Bool.h"

void UEnemyBlackboard::PostLoad()
{
    Super::PostLoad();

    //目的地
    FBlackboardEntry Destination;
    Destination.EntryName = FName("Destination");
    UBlackboardKeyType_Vector* DestinationKeyType = NewObject();
    Destination.KeyType = DestinationKeyType;

    //敌人状态
    FBlackboardEntry EnemyState;
    EnemyState.EntryName = FName("EnemyState");
    UBlackboardKeyType_Enum* EnemyStateKeyType = NewObject();
    EnemyStateKeyType->EnumType = FindObject(ANY_PACKAGE, *FString("EEnemyAIState"), true);
    EnemyStateKeyType->EnumName = FString("EEnemyAIState");
    EnemyState.KeyType = EnemyStateKeyType;

}

UBTDecorator:

//对应的就是蓝图节点的PerformConditionCheck
        virtual bool CalculateRawConditionValue(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory) const override;

使用导航系统获取随机点
    UNavigationSystem::K2_GetRandomReachablePointInRadius(SEController, ChaseOrigin, DesLoc, ChaseRadius);

重写task执行函数

virtual EBTNodeResult::Type ExecuteTask(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory) override;

 

保存文件4.24（编辑器）

UDataTable* saveTble;
        TArray PackagesToSave;
        PackagesToSave.Add(saveTble->GetOutermost());
        UEditorLoadingAndSavingUtils::SavePackages(PackagesToSave, false);
        UE_LOG(LogTemp, Warning, TEXT("Save %s SUCCESS!"), *saveTble->GetName());