UE4 c++ cast的用法
.CPP中先獲取要cast的類的.h頭文件
在獲取Kismet/GameplayStatics.h
#include"Public/Character/GameCharacter.h"//自己想cast的類
#include"Kismet/GameplayStatics.h"
AGameCharacter*MyCharacter=Cast<AGameCharacter>(UGameplayStatics::GetPlayerPawn(this,0));
UE4 switch 整數的用法
在.H裏面創建一個整數
int32 Number;
.cpp
switch(Number)
{
default:
break;
case 1:
Number=2;//你想做的事情
break;
case 2:
Number=1;//你想做的事情
break;
}
UE4獲取Character類中默認的SkeletalMesh
GetMesh()->
UE4使用動畫蒙太奇
先創建一個animmontage
.h
UPROPERTY(EditDefaultsOnly, Category = "AnimMontage")
class UAnimMontage*AttackAnim1;
.cpp
#include "Animation/AnimMontage.h"
在函數中寫
PlayAnimMontage(AttackAnim1);
UE4文件使用
文件操作類:FFileHelper
可用於創建txt
FFileHelper::SaveStringToFile(const FString& Content,
const TCHAR* Filename,
EEncodingOptions EncodingOptions = EEncodingOptions::AutoDetect,
IFileManager* FileManager = &IFileManager::Get(),
uint32 WriteFlags = 0 );
在自己定義的類中定義
FFileHelper::SaveStringToFile("\r\n"+Content, *Filename);
文件操作類:IPlatformFile
IPlatformFile& fileManager=FPlatformFileManager::Get().GetPlatformFile();//對IPlatformfile進行實例化後面進行調用
fileManager.CreateDirectoryTree(const TCHAR*Directory);
fileManager.DeleteFile();
路徑操作類: FPaths
FPaths::RootDir();//返回根目錄路徑
FPaths::ProjectDir();//返回項目所在文件夾路徑,注意:4.18版本爲 GameDir();已經無法在新版中使用
FPaths::ProjectConfigDir();//返回項目配置文件夾路徑
FPaths::RemoveDuplicateSlashes(FString& InPath);//刪除InPath中重複的斜槓
FPaths::ConvertRelativePathToFull(const FString& InPath);//將相對路徑轉換爲絕對路徑並返回
Overlap(C++)
.H
UPPROPERTY()
class UBoxComponent*CapusleComp;
UFUNCTION()
void OnOverlapBegin(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex,bool bFromSweep, const FHitResult & SweepResult);
UFUNCTION()
void OnOverlapEnd(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);
.CPP
AActor::AActor()
{
CapusleComp=CreateDefaultSubobject<UBoxComponent>(TEXT("CapusuleComp"));
CapusleComp->SetupAttachment(Rootment);
CapusleComp->SetBoxExtent(FVector(20.0f,20.0f,20.0f));
CapusleComp->bDynamicObstacle=true;
CapusleComp->bGenerateOverlapEvents=true;
CapusleComp->SetCollisionResponseToAllChannels(ECR_Overlap);
FScriptDelegate DelegateBegin;
DelegateBegin.BindUFunction(this,"OnOverlapBegin");
CaapusleComp->OnComponentBeginOverlap.Add(DelegateBegin);
}
void AActor:: OnOverlapBegin(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex,bool bFromSweep, const FHitResult & SweepResult)
{
GEngine->AddOnScreenDebugMessage(-1,2.0f,FColor::Yellow,FString("ss"));
}
靜態加載ConstructorHelpers
.cpp
#include"UObject/ConstructorHelpers.h"
AActor::AActoe()
{
有兩種,一種是FObjectFinder,另一種是FClassFinder
static ConstructorsHelpers::FObjectFinder<USkeleltalMesh>GameCharacterSkeletal(TEXT("SkeletalMesh'/Game/PolygonTown/Meshes/Characters/SK_Character_Son_01.SK_Character_Son_01'"));
//加載模型物體等用object,這樣寫沒錯。
static ConstructorHelper::FClassFinder<UAnimInstance>Gameinstance(TEXT("AnimBlueprint'/Game/Character/NewAnimBlueprint.NewAnimBlueprint_C'"));
//這個ClassFinder如果按FObjectFinder寫會錯誤提示找不到類,需要在位置最後面增加_C,或者把位置寫成/Game/Character/NewAnimBlueprint
而且有個問題就是你要定義這個位置的類給到C++必須在後面寫到.Object和.Class
if(GameCharacterSkeletal.Succeeded())
{GetMesh->SetSkeletalMesh(GameCharacterSkeletal.Object);
GetMesh->SetAnimInstanceClass(Baseinstance.Class);
}}
Gamemode中定義Character等類
static ConstructorHelpers::FClassFinder<ABaseCharacter>BaseCharacter(TEXT("你類的地址"));
if(BaseCharacter.Succeeded())
{
DefaultPawnClass=BaseCharacter.Class;
}
或者動態加載
UBaseCharacterAnimInstance*MeshAnim=LoadObject<UBaseCharacterAnimInstance>(NULL,TEXT("/Game/Character/NewAnimBlueprint.NewAnimBlueprint"));
GetMesh()->SetAnimInstanceClass(MeshAnim);
在C++中,你寫了一個函數,你想在搜索的時候用關鍵字就可以找到他,或者你想把C++中函數的名字在藍圖中以別的名字表達出來可以用meta來實現
UFUNCTION(BlueprintCallable,meta=(DisplayName="hhh"),Keywords="GGG")
void SEE();
在藍圖中輸入關鍵字GGG就找到函數名hhh
UMG 的組件指定
.h
#include"Components/Button.h"
UPROPERTY()
UButton*StartButton;
Virtual bool Initialize()override;
.cpp
bool UStartUserWidget::Initialize()
{
if (!Super::Initialize())
{
return false;
}
StartButton = Cast<UButton>(GetWidgetFromName(TEXT("Button_Start")));
return true;
}
遊戲退出
.h
#include"Kismet/KismetSystemLibrary.h"
.cpp
UKismetSystemLibrary::QuitGame(GetWorld(),nullptr,EQuitPreference::Quit);
UE4委託DECLARE_DELEGATE使用
.h
/**在頭文件的首部寫入定義*/
DECLARE_DELEGATE(MyDelegate)
DECLARE_DELEGATE_OneParam(MyDelegate,int32)
後在進行聲明和回調函數實現,要加入UFUNCTION進行函數修飾聲明,委託是參與UE的反射系統中
MyDelegate MyDe;
UFUNCTION()
void HuiDiao();
.cpp
void 父類::HuiDiao()
{
}
在BeginPlay中加入委託綁定
void 父類::BeginPlay()
{
Super::BeginPlay();
MyDe.BindUFunction(this,FName("HuiDiao"));
}
在UE4中,當你需要用到網絡時,可以用HTTP發送Json數據給到WEB服務器或者用socket中的UDP和TCP兩個協議來發送數據到服務器,HTTP的方式如下:
1,在項目Build.cs文件裏面添加"HTTP","Json"
using UnrealBuildTool;
public class RealityGame : ModuleRules
{
public RealityGame(ReadOnlyTargetRules Target) : base(Target)
{
PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore","Json","HTTP" });
PrivateDependencyModuleNames.AddRange(new string[] { });
// Uncomment if you are using Slate UI
// PrivateDependencyModuleNames.AddRange(new string[] { "Slate", "SlateCore" });
// Uncomment if you are using online features
// PrivateDependencyModuleNames.Add("OnlineSubsystem");
// To include OnlineSubsystemSteam, add it to the plugins section in your uproject file with the Enabled attribute set to true
}
}
然後在你的類中寫入用到的函數
.h
#include "Runtime/Online/HTTP/Public/HttpModule.h"
#include "Runtime/Online/HTTP/Public/Interfaces/IHttpRequest.h"
#include "Runtime/Online/HTTP/Public/Interfaces/IHttpResponse.h"
//用戶登錄的方法
UFUNCTION()
void AccountLoginFromServer(FString Nickname,FString Password);
//回調函數,請求響應
void RequestComplete(FHttpRequestPtr RequestPtr,FHttpResponsePtr ResponsePtr,bool bIsSuccess);
.cpp
void 你的函數::AccountLoginFromServer()
{
//創建一個數據包先
FString Data;
//創建一個JsonWriter寫入器,等下用他的函數來發送
TSharedRef<TJsonWriter<TCHAR,TCondensedJsonPrintPolicy<TCHAR>>>JsonWriter=TJsonWriterFactory<TCHAR,TCondensedJsonPrintPolicy<TCHAR>>::Create(&Data);
/*打開寫入器*/
JsonWriter->WriteObjectStart();
/*寫入暱稱*/
JsonWriter->WriteValue("nickname",Nickname);
/*寫入密碼*/
JsonWriter->WriteValue("password", Password);
/*關閉寫入*/
JsonWriter->WriteObjectEnd();
/*關閉json寫入器*/
JsonWriter->Close();
/** 創建HTTP請求 */
TSharedRef<IHttpRequest>Request = FHttpModule::Get().CreateRequest();
/** 設置請求頭 */
Request->SetHeader("Content-Type", "application/json;charset=utf-8");
/** 設置請求方式 */
Request->SetVerb("POST");
/** 設置請求的內容 */
Request->SetContentAsString(Data);
/** 請求的URL */
Request->SetURL("http://192.168.191.1:7900/user/login-user");
/** 設置請求成功的回調方法 */
Request->OnProcessRequestComplete().BindUObject(this,&ULoginUserWidget::RequestComplete);
/** 開始處理請求 */
Request->ProcessRequest();
}
/** 請求的響應方法 */
void ULoginUserWidget::RequestComplete(FHttpRequestPtr RequestPtr, FHttpResponsePtr ResponsePtr, bool bIsSuccess)
{ /** 加載框設置隱藏 */
CircularThrobber->SetVisibility(ESlateVisibility::Hidden);
/** 設置登錄按鈕可用狀態 */
LoginButton->SetIsEnabled(true);
/** 判斷響應的狀態 */
if (!EHttpResponseCodes::IsOk(ResponsePtr->GetResponseCode()))
{
return;
}
/** 創建Json解析器 */
TSharedRef<TJsonReader<TCHAR>>JsonReader = TJsonReaderFactory<TCHAR>::Create(ResponsePtr->GetContentAsString());
/** 創建Json對象 */
TSharedPtr<FJsonObject>JsonObject;
/** 反序列化Json */
bool bIsOk = FJsonSerializer::Deserialize(JsonReader, JsonObject);
/** 判斷是否反序列化成功 */
if (bIsOk)
{ /** 獲取返回數據的msg */
FString Msg = JsonObject->GetStringField("msg");
/** 獲取返回的數據的data */
TSharedPtr<FJsonObject>JsonData = JsonObject->GetObjectField("data");
/** 從data中獲取用戶的id */
FString Id = JsonData->GetStringField("id");
/** 從data中獲取用戶的nickname */
FString NickName = JsonData->GetStringField("nickname");
}