UE4 动态读写Datable，自己也能写数据库了

一、前期准备

创建数据表格，放入到Content目录下面命名为DataTableFile（后面会用到），根据你们自己来就行，，Datable格式为CSV（不懂可以查看百度）

数据类型与下面自定义的数据类型相同

二、自定义结构体

C++创建一个UObject的类，命名一个结构体

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "UObject/NoExportTypes.h"
#include"Engine/Classes/Engine/DataTable.h"
#include "MyObject.generated.h"

/**
 * 
 */

USTRUCT(BlueprintType)
struct FYourCppStruct : public FTableRowBase
{
	GENERATED_USTRUCT_BODY()

		UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "YourCppStruct")
		int32 IntegerValue;

	UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "YourCppStruct")
		float FloatValue;

	UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "YourCppStruct")
		FString StingValue;

};
UCLASS()
class DASD_API UMyObject : public UObject
{
	GENERATED_BODY()
	
};

三、导入Datatable，选择自定义的数据结构

 四、C++创建一个BlueprintLibrary类

#include "CoreMinimal.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "Engine/DataTable.h"
#include "HAL/PlatformFilemanager.h"
#include "Misc/FileHelper.h"
#include "Misc/Paths.h"
#include "Engine/DataTable.h"
#include "GenericArrayLibrary.generated.h"


//动态读取DataTable数据表格......
	UFUNCTION(BlueprintCallable, DisplayName = "Fill Data Table from CSV String", Category = "DataTable")
		static bool FillDataTableFromCSVString(UDataTable* DataTable, const FString& CSVString);

	UFUNCTION(BlueprintCallable, DisplayName = "Fill Data Table from CSV File", Category = "DataTable")
		static bool FillDataTableFromCSVFile(UDataTable* DataTable, const FString& CSVFilePath);

	UFUNCTION(BlueprintCallable, DisplayName = "Fill Data Table from JSON String", Category = "DataTable")
		static bool FillDataTableFromJSONString(UDataTable* DataTable, const FString& JSONString);

	UFUNCTION(BlueprintCallable, DisplayName = "Fill Data Table from JSON File", Category = "DataTable")
		static bool FillDataTableFromJSONFile(UDataTable* DataTable, const FString& JSONFilePath);

	UFUNCTION(BlueprintCallable, DisplayName = "Get Table As CSV String", Category = "DataTable")
		static void GetDataTableAsCSVString(UDataTable* DataTable, FString& CSVString);

	UFUNCTION(BlueprintCallable, DisplayName = "Get Table As CSV File", Category = "DataTable")
		static void GetDataTableAsCSVFile(UDataTable* DataTable, const FString& CSVFilePath);

bool UGenericArrayLibrary::FillDataTableFromCSVString(UDataTable* DataTable, const FString& CSVString)
{
	if (!DataTable || (CSVString.Len() == 0))
	{

		return false;
	}
	// Call bulit-in function
	TArray<FString> Errors = DataTable->CreateTableFromCSVString(CSVString);
	if (Errors.Num())
	{
		// It has some error message
		for (const FString& Error : Errors)
		{
			UE_LOG(LogTemp, Warning, TEXT("error1"));
		}
		return false;
	}
	UE_LOG(LogTemp, Warning, TEXT("true"));
	return true;
	
}

bool UGenericArrayLibrary::FillDataTableFromCSVFile(UDataTable* DataTable, const FString& CSVFilePath)
{
	FString CSVString;
	if (FPlatformFileManager::Get().GetPlatformFile().FileExists(*CSVFilePath))
	{
		// Supports all combination of ANSI/Unicode files and platforms.
		FFileHelper::LoadFileToString(CSVString, *CSVFilePath);
	}
	else
	{
		UE_LOG(LogTemp, Warning, TEXT("error2"));
		return false;
	}
	return UGenericArrayLibrary::FillDataTableFromCSVString(DataTable, CSVString);
	UE_LOG(LogTemp, Warning, TEXT("success"));
}

bool UGenericArrayLibrary::FillDataTableFromJSONString(UDataTable* DataTable, const FString& JSONString)
{
	if (!DataTable || (JSONString.Len() == 0))
	{

		return false;
	}
	// Call bulit-in function
	TArray<FString> Errors = DataTable->CreateTableFromJSONString(JSONString);

	if (Errors.Num())
	{
		// It has some error message
		for (const FString& Error : Errors)
		{

		}
		return false;
	}

	return true;
}

bool UGenericArrayLibrary::FillDataTableFromJSONFile(UDataTable* DataTable, const FString& JSONFilePath)
{
	FString JSONString;
	if (FPlatformFileManager::Get().GetPlatformFile().FileExists(*JSONFilePath))
	{
		// Supports all combination of ANSI/Unicode files and platforms.
		FFileHelper::LoadFileToString(JSONString, *JSONFilePath);
	}
	else
	{

		return false;
	}
	return UGenericArrayLibrary::FillDataTableFromJSONString(DataTable, JSONString);
}

void UGenericArrayLibrary::GetDataTableAsCSVString(UDataTable* DataTable, FString& CSVString)
{
	CSVString = FString();

	if (!DataTable || (DataTable->RowStruct == nullptr))
	{

		return;
	}

	// First build array of properties
	TArray<FProperty*> StructProps;
	for (TFieldIterator<FProperty> It(DataTable->RowStruct); It; ++It)
	{
		FProperty* Prop = *It;
		check(Prop != nullptr);
		StructProps.Add(Prop);
	}

	// First row, column titles, taken from properties
	CSVString += TEXT("---");
	for (int32 PropIdx = 0; PropIdx < StructProps.Num(); PropIdx++)
	{
		CSVString += TEXT(",");
		CSVString += StructProps[PropIdx]->GetName();
	}
	CSVString += TEXT("\n");

	// Now iterate over rows
	for (auto RowIt = DataTable->GetRowMap().CreateConstIterator(); RowIt; ++RowIt)
	{
		FName RowName = RowIt.Key();
		CSVString += RowName.ToString();

		uint8* RowData = RowIt.Value();
		for (int32 PropIdx = 0; PropIdx < StructProps.Num(); PropIdx++)
		{
			CSVString += TEXT(",");
			CSVString += DataTableUtils::GetPropertyValueAsString(StructProps[PropIdx], RowData, EDataTableExportFlags::None);
		}
		CSVString += TEXT("\n");
	}
}

void UGenericArrayLibrary::GetDataTableAsCSVFile(UDataTable* DataTable, const FString& CSVFilePath)
{
	FString CSVString;
	UGenericArrayLibrary::GetDataTableAsCSVString(DataTable, CSVString);
	if (CSVString.Len() == 0)
	{
		return;
	}
	FFileHelper::SaveStringToFile(CSVString, *CSVFilePath, FFileHelper::EEncodingOptions::ForceUTF8);
}

四、蓝图实现