一、前期操作

创建一个C++项目，并且创建一个C++蓝图库函数，并且加入头文件

#include "HAL/PlatformFilemanager.h"
#include "Misc/FileHelper.h"
#include "Misc/Paths.h"
#include "Developer/DesktopPlatform/Public/DesktopPlatformModule.h"
#include "Developer/DesktopPlatform/Public/IDesktopPlatform.h"
#include "Runtime/Core/Public/HAL/FileManagerGeneric.h"

 二、打开文件

UFUNCTION(BlueprintCallable, DisplayName = "OpenFile", Category = "File")static TArray<FString> OpenFile();

TArray<FString> UGenericArrayLibrary::OpenFile()
{TArray<FString> FilePath; //选择文件路径FString fileType = TEXT("*.*"); //过滤文件类型FString defaultPath = FPaths::ConvertRelativePathToFull(FPaths::ProjectDir()); //文件选择窗口默认开启路径IDesktopPlatform* DesktopPlatform = FDesktopPlatformModule::Get();bool bSuccess = DesktopPlatform->OpenFileDialog(nullptr, TEXT("打开文件"), defaultPath, TEXT(""), *fileType, EFileDialogFlags::None, FilePath);for (auto& name : FilePath){UE_LOG(LogTemp, Warning,TEXT("%s"), *name);}if (bSuccess){//文件选择成功，文件路径 path UE_LOG(LogTemp,Warning,TEXT("Success"));}return FilePath;
}

三、读取和写入文件（字符串）

//读取文件(字符串)UFUNCTION(BlueprintCallable, DisplayName = "ReadFile", Category = "File")static FString ReadFile(FString path);
//写入文件(字符串)UFUNCTION(BlueprintCallable, DisplayName = "WriteFile", Category = "File")static bool WriteFile(FString saveFile,FString path);

FString UGenericArrayLibrary::ReadFile(FString path)
{FString resultString;FFileHelper::LoadFileToString(resultString,*path);return resultString;
}
///
bool UGenericArrayLibrary::WriteFile(FString saveFile,FString path)
{bool success;success = FFileHelper::SaveStringToFile(saveFile,*path);return success;
}

 四、读取和写入字符数组

/读取文件(字符数组)UFUNCTION(BlueprintCallable, DisplayName = "ReadFileArray", Category = "File")static TArray<FString> ReadFileArray(FString path);//写入文件(字符数组)UFUNCTION(BlueprintCallable, DisplayName = "WriteFileArray", Category = "File")static bool WriteFileArray(TArray<FString> saveFile,FString path);

TArray<FString> UGenericArrayLibrary::ReadFileArray(FString path)
{TArray<FString> results;FFileHelper::LoadFileToStringArray(results, *path);return results;
}bool UGenericArrayLibrary::WriteFileArray(TArray<FString> saveFile, FString path)
{return FFileHelper::SaveStringArrayToFile(saveFile,*path);
}

五、 获取文件路径，获取文件名，获取文件后缀

	//获取文件所在路径UFUNCTION(BlueprintCallable, DisplayName = "Get FilePath", Category = "File")static FString GetFilePath(FString path);//获取文件名，不带后缀UFUNCTION(BlueprintCallable, DisplayName = "GetFileName", Category = "File")static FString GetFileName(FString InPath, bool bRemovePath);//获取文件后缀UFUNCTION(BlueprintCallable, DisplayName = "GetFileExtension", Category = "File")static FString GetFileExtension(FString InPath, bool bIncludeDot);

FString UGenericArrayLibrary::GetFilePath(FString path)
{FString Result;Result = FPaths::GetPath(*path);return Result;
}FString UGenericArrayLibrary::GetFileName(FString InPath, bool bRemovePath)
{return FPaths::GetBaseFilename(*InPath,bRemovePath);
}FString UGenericArrayLibrary::GetFileExtension(FString InPath, bool bIncludeDot)
{return FPaths::GetExtension(*InPath,bIncludeDot);
}

六、增加一个文件夹 和删除一个文件夹

//创建一个文件夹UFUNCTION(BlueprintCallable, DisplayName = "CreateFolder", Category = "File")static void CreatFolder(FString FolderName);
//删除一个文件夹UFUNCTION(BlueprintCallable, DisplayName = "DeleteFolder", Category = "File")static void DeleteFolder(FString FolderName);

void UGenericArrayLibrary::CreatFolder(FString FolderName)
{FString Path = FPaths::ProjectDir()/ *FolderName;Path = FPaths::ConvertRelativePathToFull(*Path);FPlatformFileManager::Get().GetPlatformFile().CreateDirectoryTree(*Path);
}void UGenericArrayLibrary::DeleteFolder(FString FolderName)
{FString Path = FPaths::ProjectDir() / *FolderName;Path = FPaths::ConvertRelativePathToFull(*Path);FPlatformFileManager::Get().Get().GetPlatformFile().DeleteDirectoryRecursively(*Path);
}

 七、移动文件夹

//移动文件UFUNCTION(BlueprintCallable, Category = "MoveFileTo")static bool MoveFileTo(FString To, FString From);

bool UGenericArrayLibrary::MoveFileTo(FString To, FString From)
{return IFileManager::Get().Move(*To, *From);
}

八、查找文件夹

//查找文件目录下的所有文件UFUNCTION(BlueprintCallable, DisplayName = "FindFolder", Category = "File")static TArray<FString> FindFolder(FString Path, FString Filter, bool Files, bool Directory);//查找文件目录下所有文件无法删选查找UFUNCTION(BlueprintCallable, DisplayName = "GetFolderFiles", Category = "File")static TArray<FString> GetFolderFiles(FString Path);

TArray<FString> UGenericArrayLibrary::FindFolder(FString Path, FString Filter, bool Files, bool Directory)
{TArray<FString> FilePathList;FilePathList.Empty();FFileManagerGeneric::Get().FindFilesRecursive(FilePathList, *Path, *Filter, Files, Directory);return FilePathList;}
//TArray<FString> UGenericArrayLibrary::GetFolderFiles(FString Path)
{TArray<FString> Files;FPaths::NormalizeDirectoryName(Path);IFileManager& FileManager = IFileManager::Get();FString FinalPath = Path / TEXT("*");FileManager.FindFiles(Files, *FinalPath, true, true);return Files;
}