macOS 获取文件夹大小

获取文件夹大小的扩展如下：

extension URL {var fileSize: Int? { // in bytesdo {let val = try self.resourceValues(forKeys: [.totalFileAllocatedSizeKey, .fileAllocatedSizeKey])return val.totalFileAllocatedSize ?? val.fileAllocatedSize} catch {print(error)return nil}}
}
extension FileManager {func folderSize(_ dir: URL) -> Int? {if let enumerator = self.enumerator(at: dir, includingPropertiesForKeys: [.totalFileAllocatedSizeKey, .fileAllocatedSizeKey], options: [], errorHandler: { (_, error) -> Bool inprint(error)return false}) {var bytes = 0for case let url as URL in enumerator {bytes += url.fileSize ?? 0}return bytes} else {return nil}}
}

但是返回来的是字节数，如果要转换成 MB 或者 GB，需要自己做转换，那再来扩展吧。

extension FileManager {func convertBytesToReadableUnit(_ bytes: Int64) -> String {let formatter = ByteCountFormatter()formatter.countStyle = .binaryformatter.allowedUnits = [.useAll]formatter.includesUnit = trueformatter.isAdaptive = truereturn formatter.string(fromByteCount: bytes)}
}let bytes: Int64 = 123456789
let readableUnit = FileManager.default.convertBytesToReadableUnit(bytes)
print(readableUnit) // Output: "117.7 MB"