UE4 C++ serialization and deserialization

 

对以下 JSON 文件进行读写操作（序列化与反序列化）。

 

{
	"nested":
	{
		"id": "i am nested id",
		"name": "this is the nested name"
	},
	"foo": "i am test foo",
	"bar_arr": [
		{
			"barfoo": "i am barfoo test"
		}
	]
}

 

定义好反序列化的文件对象结构：

 

USTRUCT()
struct FNested
{
    GENERATED_USTRUCT_BODY()

    UPROPERTY()
    FString id;

    UPROPERTY()
    FString name;
};

USTRUCT()
struct FBar
{
    GENERATED_USTRUCT_BODY()

    UPROPERTY()
    FString barfoo;
};

USTRUCT()
struct FJsonData
{
    GENERATED_USTRUCT_BODY()

    UPROPERTY()
    FNested nested;

    UPROPERTY()
    FString foo;

    UPROPERTY()
    TArray<FBar> bar_arr;

    //Transient 会阻止该属性被序列化
    UPROPERTY(Transient)
    FString PropertyToIgnore;
};

 

读写操作：

void UJsonSerializeComponent::Read() 
{
	FString FilePath = "F:\\svn-master\\thirdparty-master\\JsonSerializeSample\\Content\\test.json";
	FString FileData = "";
	if (!FPlatformFileManager::Get().GetPlatformFile().FileExists(*FilePath))
	{
		UE_LOG(LogTemp, Warning, TEXT("DID NOT FIND FILE"));
		return;
	}

	FJsonData JsonData;
	FFileHelper::LoadFileToString(FileData, *FilePath);

	UE_LOG(LogTemp, Warning, TEXT("%s"), *FileData);

	if (FJsonObjectConverter::JsonObjectStringToUStruct(FileData, &JsonData, 0, 0))
	{
		UE_LOG(LogTemp, Warning, TEXT("CONVERTED"));
		UE_LOG(LogTemp, Warning, TEXT("NestedName: %s "), *JsonData.nested.name);
	}
}

void UJsonSerializeComponent::Write() 
{
	FJsonData JsonData;
	JsonData.nested.id = "i am nested id2";
	JsonData.nested.name = "this is the nested name2";
	JsonData.foo = "i am test foo2";
	FBar bar;
	bar.barfoo = "i am barfoo test2";
	JsonData.bar_arr.Add(bar);

	FString JsonString;
	FJsonObjectConverter::UStructToJsonObjectString(JsonData, JsonString);

	//save to file
	FFileHelper::SaveStringToFile(JsonString, *FString("F:\\svn-master\\thirdparty-master\\JsonSerializeSample\\Content\\test.json"));
}

 

记得要在 PublicDependencyModuleNames 中加入 "Json" 和  "JsonUtilities" 模块。