UE4 C++常用代码及格式
1.Debug相关
LOG Debug
UE_LOG(LogTemp,Warning,Text(“Bginplay”));在屏幕显示文字
GEngine->AddOnScreenDebugMessage(-1,5.f,FColor::Black,Text(“Beginplay”));2.常用数据类型变化
int变为Int8 int16 int32 int64
string 变为 FString
新增FVector等类型
3.各继承类型前缀代表含义
A --Actor
F--Other
U--UE4
E--Enum
I--Interface
T--Template
S --Slate
4.宏 暴露变量给蓝图
UPROPERTY(EditAnywhere,BlueprintReadWrite,/*VisibleAnywhere,BlueprintReadOnly*/)
Float Health = 100;5.宏 暴露函数给蓝图
.h //普通节点
UFUNCTION(BlueprintCallable, Category = “MyActorFunction”) //Category给节点分组
void PrintAString(FString String, UPARAM(Ref) int32& a,FString& OutString);
.cpp
void AMyActor::PrintAString(FString String, UPARAM(Ref) int32& a,FString& OutString) //通过UPARAM(Ref) 数据类型& 引用传入值
{
GEngine->AddOnScreenDebugMessage(-1,5.f,FColor::Black,String);
OnGetPrintString(string); //调用下面的可执行事件
OutString = “OK”; //通过FString&引用，获得返回值
}
.h //事件节点类型1，不需要.cpp文件
UFUNCTION(BlueprintImplementableEvent, Category = “MyActorFunction”) //不能在C++里写节点的内容
Void OnGetPrintString(const FString& String);.h //事件节点类型2
UFUNCTION(BlueprintNativeEvent, /*BlueprintCallable,*/ Category = “MyActorFunction”) //可以在C++里写东西，但是会被蓝图覆盖,BlueprintCallable出来的节点内容会被该事件屏蔽
Void OnGetPrintString(const FString& String);
virtual void OnGetPrintString_Implementation(const FString& String);
.cpp
void AMyActor::OnGetPrintString_Implementation(const FString& String)
{
GEngine->AddOnScreenDebugMessage(-1,5.f,FColor::Green,String);
}.h
UFUNCTION(BlueprintPure) //BlueprintPure定义纯函数，一般都有返回值
float GetHealth();
.cpp
float AMyActor::GetHealth() //可借鉴const FString& String返回多个值
{
return Health;
}6.多播代理
.h
#include下方定义
DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FMyDelegate, FString,Sting);
UPROPERTY(BlueprintAssignable)
FMyDelegate MyDelegate;
.cpp
Void AMyActor::BeginPlay()//例如在BeginPlay时引用
{
Super::BeginPlay();
MyDelegate.Broadcast(“BeginPlay”);
}7.单播代理
.h
#include下方定义
DECLARE_DYNAMIC_DELEGATE_OneParam(FMyDelegateOne, float,Sting);
UFUNCTION(BlueprintCallable)
void DelegateTest(FMyDelegateOne MyDelegateOne);
.cpp
Void AMyActor::DelegateTest(FMyDelegateOne MyDelegateOne)
{
HealthPercentage = Health/MaxHealth;
DelegateOne.Execute(Healthpercentage);
}8.结构体
.h
#include下方定义
USTRUCT(BuleprintType)
struct FHealth
{
GENERATED_BODY()
UPROPERTY(EditAnywhere,BlueprintReadWrite)
Float Health = 100;
UPROPERTY(EditAnywhere,BlueprintReadWrite)
Float MaxHealth = 100;
UPROPERTY(VisibleAnywhere,BlueprintReadOnly)
Float HealthPercentage = Health / MaxHealth;
};
UPROPERTY(EditAnywhere,BlueprintReadWrite)
FHealth HealthS; //C++使用时可HealthS.Healthu提取，蓝图使用时可直接调用也可先Split Struct Pin解开结构体9.枚举
.h
#include下方定义
UENUM(BuleprintType)
enum class EMyENumType :uint8
{
Data1, //蓝图创建Enum变量，get变，switch提取变量
E_Data2 UMETA=(DisplayName=”Data2”), //蓝图中屏蔽E_前缀，便于在代码中区分变量，而蓝图中仍显示为Data2
Data3,
//...
};
UPROPERTY(EditAnywhere,BlueprintReadWrite)
EMyENumType MyENumType = EMyENumType::Data1;10.数组
.h
UFUNCTION(BlueprintCallable)
void PrintAllString(TArray StringArray);
.cpp
Void PrintAllString(TArray StringArray)
{
For(FString Each : StringArray) //等同于FoeEachLoop
{
GEngine->AddOnScreenDebugMessage(-1,5.f,FColor::Green,Each);
}
} 11.元数据说明符
.h //使用方法
UFUNCTION(BlueprintPure,meta=(displayname = “CustomName”,Keywords=”CustomKeywords”, DevelopmentOnly/*,...*/)) //meta=(按所需功能填写)
Float MyFunction()
.cpp
Float AMyActor::MyFunction()
{
Return 0.f;
}.h //一个例子，给蓝图引脚定义默认值
UFUNCTION(BlueprintCallable,meta=(AutoCreateRefTerm="b")) //不添加AutoCreateRefTerm则引脚必须从上一节点处获取参数
void MyInput(int a, UPARAM(Ref) int32& b);
.cpp
void AMyActor::MyInput(int a, UPARAM(Ref) int32& b) //通过UPARAM(Ref) 数据类型& 引用 在蓝图中传入值
{
//随便写
}
以上内容参考自@暂无名讳和官方文档