【UE4 C++】读写Text文件 FFileHelper

CoreMisc.h

读取

FFileHelper::LoadFileToString

• 读取全部内容，存到 FString

  FString TextPath = FPaths::ProjectDir() + TEXT("DataDrive/Dialogue.txt");
  TextPath = FPaths::ConvertRelativePathToFull(TextPath);
  if (FPlatformFileManager::Get().GetPlatformFile().FileExists(*TextPath))
  {
  	FString TextData;
  	FFileHelper::LoadFileToString(TextData, *TextPath);
  	UE_LOG(LogTemp, Warning,TEXT("%s"), *TextData);
  }
  

FFileHelper::LoadFileToStringArray

• 读读取全部内容，存到 TArray中，每个元素代表一行

  FString TextPath = FPaths::ProjectDir() + TEXT("DataDrive/Dialogue.txt");
  	TextPath = FPaths::ConvertRelativePathToFull(TextPath);
  	if (FPlatformFileManager::Get().GetPlatformFile().FileExists(*TextPath))
  	{
  		TArray<FString> TextData;
  		FFileHelper::LoadFileToStringArray(TextData, *TextPath);
  		int32 line = 0;
  		for (FString lineContent : TextData)
  		{
  			UE_LOG(LogTemp, Warning, TEXT("[line %d] %s"), ++line, *lineContent);
  		}
  	}
  

  

写入

SaveStringToFile

• 字符串写入文件，需要手动嘉 \n 换行

• 注意字符编码

• 注意WriteFlags，参考下面 EFileWrite 枚举

• Syntax

  enum EFileWrite
   {
       FILEWRITE_NoFail            = 0x01,
       FILEWRITE_NoReplaceExisting = 0x02,
       FILEWRITE_EvenIfReadOnly    = 0x04,
       FILEWRITE_Append            = 0x08,
       FILEWRITE_AllowRead         = 0x10
   };
  
  bool FFileHelper::SaveStringToFile( FStringView String, const TCHAR* Filename,  EEncodingOptions EncodingOptions, IFileManager* FileManager /*= &IFileManager::Get()*/, uint32 WriteFlags )
  

• 代码实现

  FString TextContent = TEXT("明知无法战胜，明知毫无意义，但还是持续挑战着的姿态，那正是我的过错。----英灵卫宫 \n");
  FFileHelper::SaveStringToFile(TextContent, *TextPath, FFileHelper::EEncodingOptions::ForceUTF8, &IFileManager::Get(), EFileWrite::FILEWRITE_Append);
  
  TextContent = TEXT("束缚于肉体中的你们，永远无法满足 ----吉尔伽美什 \n");
  FFileHelper::SaveStringToFile(TextContent, *TextPath, FFileHelper::EEncodingOptions::ForceUTF8, &IFileManager::Get(), EFileWrite::FILEWRITE_Append);
  

• 支持导出CSV

  UserInfoDataTable = LoadObject<UDataTable>(this, TEXT("DataTable'/Game/CPPFunction/DataDrive/DT_UserInfo.DT_UserInfo'"));
  if (UserInfoDataTable)
  {
  	FString CSVString = UserInfoDataTable->GetTableAsCSV();
  	FString CSVPath = FPaths::ProjectDir() + TEXT("DataDrive/UserInfo2.csv");
  	FFileHelper::SaveStringToFile(CSVString, *CSVPath, FFileHelper::EEncodingOptions::ForceUTF8);
  }
  

SaveStringArrayToFile

• 字符串数组写入文件，自动换行

• 如果保存中文乱码，点击高级保存为UTF8格式

• Syntax

  bool FFileHelper::SaveStringArrayToFile( const TArray<FString>& Lines, const TCHAR* Filename, EEncodingOptions EncodingOptions, IFileManager* FileManager, uint32 WriteFlags )
  

• 代码实现

  FString TextPath = FPaths::ProjectDir() + TEXT("DataDrive/FateNight.txt");
  TextPath = FPaths::ConvertRelativePathToFull(TextPath);
  TArray<FString> TextLines;
  TextLines.Add(TEXT("钢铁为身，而火焰为血。"));
  TextLines.Add(TEXT("手制之剑已达千余，纵横无数战场而不败。"));
  TextLines.Add(TEXT("不知生。"));
  TextLines.Add(TEXT("亦不知死。"));
  TextLines.Add(TEXT("未曾一次败退。"));
  TextLines.Add(TEXT("常独自一人立于剑丘之巅独醉于胜利中。"));
  TextLines.Add(TEXT("然而 留下的只有虚无。"));
  TextLines.Add(TEXT("故此 此生已无意义。"));
  TextLines.Add(TEXT("则此躯 注定为剑而生。"));
  TextLines.Add(TEXT("故我祈求——无限之剑制(Unlimited Blade Works)"));
  FFileHelper::SaveStringArrayToFile(TextLines, *TextPath,FFileHelper::EEncodingOptions::ForceUTF8);