Unable to cast object of type 'System.IO.FileSystemInfo[]' to type 'System.Collections.Generic.IEnumerable`1[System.IO.DirectoryInfo]

Question

I have been trouble with an cast error for the following method in a PCL which I have no issues with in a legacy class library.

    protected FolderInfo GetFolderInfo(string folderPath, int level = 0)
    {
        FolderInfo folderInfo = new FolderInfo(folderPath);

        if (settings.MaxDepthLevel == 0 || level < settings.MaxDepthLevel)
        {
            try
            {
                DirectoryInfo currentDirectoryInfo = new DirectoryInfo(folderPath);

                foreach (DirectoryInfo directoryInfo in currentDirectoryInfo.GetDirectories())
                {
                    if (settings.SkipHiddenFolders && directoryInfo.Attributes.HasFlag(FileAttributes.Hidden))
                    {
                        continue;
                    }

                    FolderInfo subFolderInfo = GetFolderInfo(directoryInfo.FullName, level + 1);
                    folderInfo.Folders.Add(subFolderInfo);
                    subFolderInfo.Parent = folderInfo;
                }

                foreach (FileInfo fileInfo in currentDirectoryInfo.EnumerateFiles())
                {
                    if (settings.SkipHiddenFiles && fileInfo.Attributes.HasFlag(FileAttributes.Hidden))
                    {
                        continue;
                    }

                    folderInfo.Files.Add(fileInfo);
                }

                folderInfo.Files.Sort((x, y) => x.Name.CompareTo(y.Name));
            }
            catch (UnauthorizedAccessException)
            {
            }
        }

        return folderInfo;
    }

I get the following error:

Exception thrown: 'System.InvalidCastException' in System.IO.FileSystem.dll Additional information: Unable to cast object of type 'System.IO.FileSystemInfo[]' to type 'System.Collections.Generic.IEnumerable`1[System.IO.DirectoryInfo]'.

In a PCL, how differently could I write this above 'working' code to behave differently?

Thanks and best regards Michael

Answer 1

Windows Phone applications do not use the file system of the operating system and are restricted to using isolated storage to persist and access files, so this namespace does not provide any additional functionality.

http://msdn.microsoft.com/en-us/library/windowsphone/develop/system.io%28v=vs.105%29.aspx

You should also take a look at this SO answer.