vault backup: 2024-10-12 17:19:45

03-UnrealEngine/Gameplay/UObject/UnrealSpecifiers/Specifier/UPROPERTY/Config/Config.md

@@ -0,0 +1,13 @@
+# Config
+
+- **功能描述：** 指定该属性是一个配置属性，该属性可以被序列化读写到ini文件（路径由uclass的config标签指定）中。
+- **元数据类型：** bool
+- **引擎模块：** Config
+- **作用机制：** [CPF_Config](../../../Flags/EPropertyFlags/CPF_Config.md)
+- **常用程度：** ★★★
+
+指定该属性是一个配置属性，该属性可以被序列化读写到ini文件（路径由uclass的config标签指定）中。
+
+在载入的时候会自动从ini中加载。如果没再加写标记，则会隐含该属性为ReadOnly。
+
+参见UCLASS中的config标记的示例代码和效果。

03-UnrealEngine/Gameplay/UObject/UnrealSpecifiers/Specifier/UPROPERTY/Config/GlobalConfig/GlobalConfig.md

@@ -0,0 +1,130 @@
+# GlobalConfig
+
+- **功能描述：** 和Config一样指定该属性可作为配置读取和写入ini中，但只会读取写入到配置文件里基类的值，而不会使用配置文件里子类里的值。
+- **元数据类型：** bool
+- **引擎模块：** Config
+- **作用机制：** 在PropertyFlags中加入[CPF_GlobalConfig](../../../../Flags/EPropertyFlags/CPF_GlobalConfig.md)
+- **常用程度：** ★★★
+
+和Config一样指定该属性可作为配置读取和写入ini中，但只会读取写入到配置文件里基类的值，而不会使用配置文件里子类里的值。
+
+但是不同点在于，该属性在LoadConfig的时候，只会读取基类的ini，而不会去读取子类的ini。因为只有基类里的Ini设置在生效，相当于全局只有一个配置在生效，因此名字叫做GlobalConfig。
+
+## 示例代码：
+
+```cpp
+UCLASS(Config = MyOtherGame)
+class INSIDER_API UMyProperty_Config :public UObject
+{
+	GENERATED_BODY()
+public:
+	UPROPERTY(EditAnywhere, BlueprintReadWrite)
+	int32 MyProperty = 123;
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Config)
+	int32 MyPropertyWithConfig = 123;
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, GlobalConfig)
+	int32 MyPropertyWithGlobalConfig = 123;
+};
+
+UCLASS(Config = MyOtherGame)
+class INSIDER_API UMyProperty_Config_Child :public UMyProperty_Config
+{
+	GENERATED_BODY()
+public:
+};
+
+void UMyProperty_Config_Test::TestConfigSave()
+{
+	FString fileName = FPaths::ProjectConfigDir() / TEXT("MyOtherGame.ini");
+	fileName = FConfigCacheIni::NormalizeConfigIniPath(fileName);
+
+	{
+		UMyProperty_Config* testObject = NewObject<UMyProperty_Config>(GetTransientPackage(), TEXT("testObject"));
+
+		testObject->MyProperty = 777;
+		testObject->MyPropertyWithConfig = 777;
+		testObject->MyPropertyWithGlobalConfig = 777;
+
+		testObject->SaveConfig(CPF_Config, *fileName);
+	}
+
+	{
+		UMyProperty_Config_Child* testObject = NewObject<UMyProperty_Config_Child>(GetTransientPackage(), TEXT("testObjectChild"));
+
+		testObject->MyProperty = 888;
+		testObject->MyPropertyWithConfig = 888;
+		testObject->MyPropertyWithGlobalConfig = 888;
+
+		testObject->SaveConfig(CPF_Config, *fileName);
+	}
+}
+
+void UMyProperty_Config_Test::TestConfigLoad()
+{
+	FString fileName = FPaths::ProjectConfigDir() / TEXT("MyOtherGame.ini");
+	fileName = FConfigCacheIni::NormalizeConfigIniPath(fileName);
+
+	UMyProperty_Config* testObject = NewObject<UMyProperty_Config>(GetTransientPackage(), TEXT("testObject"));
+	testObject->LoadConfig(nullptr, *fileName);
+
+	UMyProperty_Config_Child* testObjectChild = NewObject<UMyProperty_Config_Child>(GetTransientPackage(), TEXT("testObjectChild"));
+	testObjectChild->LoadConfig(nullptr, *fileName);
+}
+```
+
+## 示例效果：
+
+TestConfigSave之后，MyPropertyWithGlobalConfig=888，可见保存的时候也只会保存在基类上。
+
+```cpp
+[/Script/Insider.MyProperty_Config]
+MyPropertyWithConfig=777
+MyPropertyWithGlobalConfig=888
+
+[/Script/Insider.MyProperty_Config_Child]
+MyPropertyWithConfig=888
+```
+
+为了测试，假如手动把配置里的值改为：然后再进行TestConfigLoad测试
+
+```cpp
+[/Script/Insider.MyProperty_Config]
+MyPropertyWithConfig=777
+MyPropertyWithGlobalConfig=888
+
+[/Script/Insider.MyProperty_Config_Child]
+MyPropertyWithConfig=888
+MyPropertyWithGlobalConfig=999
+```
+
+显示效果：
+
+可见testObjectChild 的值并没有使用ini里MyProperty_Config_Child下的999的值，而是同样的888.
+
+![image](image.png)
+
+## 原理：
+
+如果是bGlobalConfig ，会采用基类。
+
+```cpp
+void UObject::LoadConfig( UClass* ConfigClass/*=NULL*/, const TCHAR* InFilename/*=NULL*/, uint32 PropagationFlags/*=LCPF_None*/, FProperty* PropertyToLoad/*=NULL*/ )
+{
+		const bool bGlobalConfig = (Property->PropertyFlags&CPF_GlobalConfig) != 0;
+		UClass* OwnerClass = Property->GetOwnerClass();
+		
+		UClass* BaseClass = bGlobalConfig ? OwnerClass : ConfigClass;
+		if ( !bPerObject )
+		{
+			ClassSection = BaseClass->GetPathName();
+			LongCommitName = BaseClass->GetOutermost()->GetFName();
+		
+			// allow the class to override the expected section name
+			OverrideConfigSection(ClassSection);
+		}
+		
+		// globalconfig properties should always use the owning class's config file
+		// specifying a value for InFilename will override this behavior (as it does with normal properties)
+		const FString& PropFileName = (bGlobalConfig && InFilename == NULL) ? OwnerClass->GetConfigName() : Filename;
+}
+```