在 iOS 上将文件夹属性更改为隐藏（FMX、C++）

Question

我想在运行时创建一个目录并将其隐藏。使用 this example 我尝试了以下代码，它在 Win32 上运行良好，但在 iOS 构建时出错：

UnicodeString TestPath;
TestPath = System::Ioutils::TPath::GetDocumentsPath() + "\\test\\";
TDirectory::CreateDirectory(TestPath);
TFileAttributes dirattribs;
dirattribs = TDirectory::GetAttributes(TestPath);
dirattribs = dirattribs << TFileAttribute::faHidden;
TDirectory::SetAttributes(TestPath, dirattribs);

为 iOS 或 Android 构建时遇到的构建错误是 no member named 'faHidden' in 'System::Ioutils::TFileAttribute'。那么，如何在 iOS 和 Android 上更改文件夹属性？

附言使用 Rad Studio 10.3.2（C++ 生成器）。

Answer 1

faHidden 未在 Posix 系统上实现。这是 Embarcadero 的 DocWiki 中的 documented behavior。 faHidden 仅适用于 Windows。

要在 Posix 系统上创建对用户隐藏的文件夹，您可以简单地在文件夹名称前加上一个前导点：

UnicodeString TestPath = System::Ioutils::TPath::GetDocumentsPath();
#ifdef _Windows
TestPath = System::Ioutils::TPath::Combine(TestPath, _D("test"));
TDirectory::CreateDirectory(TestPath);
TFileAttributes dirattribs = TDirectory::GetAttributes(TestPath);
dirattribs = dirattribs << TFileAttribute::faHidden;
TDirectory::SetAttributes(TestPath, dirattribs);
#else
TestPath = System::Ioutils::TPath::Combine(TestPath, _D(".test"));
TDirectory::CreateDirectory(TestPath);
#endif

注意，在 Windows 上也可以创建一个带有前导点的文件夹。它不会对文件夹的隐藏属性产生影响，您仍然需要明确设置：

UnicodeString TestPath = System::Ioutils::TPath::GetDocumentsPath();
TestPath = System::Ioutils::TPath::Combine(TestPath, _D(".test"));
TDirectory::CreateDirectory(TestPath);
#ifdef _Windows
TFileAttributes dirattribs = TDirectory::GetAttributes(TestPath);
dirattribs = dirattribs << TFileAttribute::faHidden;
TDirectory::SetAttributes(TestPath, dirattribs);
#endif