UWP Parse folder from absolute or relative path

Question

I want to parse a folder that the user can choose. But if I understand, absolute paths are not allowed in UWP because the disks are not the same following the media (xbox, windows phone, windows desktop, ...) ?

So, I have a class called Parser that can parse the path that the user picks but now, only the current folder can be parsed.

This doesn't work :

Parser parser = new Parser(@"C:\a\b\c");
parser.createTreeView(tree);

Help me please. Thank you in advance.

EDIT : This is my Parser class =>

public TreeViewItem Parse(DirectoryInfo directoryInfo)
    {
        try
        {
            var directoryNode = new TreeViewItem { Header = directoryInfo.Name };
            Convention convention = new Convention();

            foreach (var directory in directoryInfo.GetDirectories())
            {

                directoryNode.Items.Add(Parse(directory));
                System.Diagnostics.Debug.WriteLine("test : " + directory.Name);
            }
            foreach (var file in directoryInfo.GetFiles())
            {
                if (file.Name.Contains(EConvention.INSTALL))
                {
                    listFiles.Add(file.FullName);
                }

                TreeViewItem item = new TreeViewItem
                {
                    Header = Path.GetFileNameWithoutExtension(file.FullName),
                    Tag = file.FullName

                };
                directoryNode.Items.Add(item);
            }
            return directoryNode;
        }
        catch (System.UnauthorizedAccessException e)
        {
            //MessageDialog dialog = new MessageDialog(""+e.Message);
            dialogAsync(e.Message);
            return new TreeViewItem();
        }

    }


public void CreateTreeView(TreeView tree)
    {

        DirectoryInfo dir = new DirectoryInfo(pathToParse);
        System.Diagnostics.Debug.WriteLine("dir exists ? "+dir.Exists);
        if (dir.Exists)
        {
            System.Diagnostics.Debug.WriteLine("dir existe");
            TreeViewItem root = new TreeViewItem() { Header = dir.Name };
            root.Tag = dir;
            tree.Items.Add(Parse(dir));
        }
    }

Answer 1

UWP apps do not have permission to access all files on the device. Apps can access certain file system locations by default. Apps can also access additional locations through the file picker, or by declaring capabilities. For more info, please see File access permissions

Although, we can use DirectoryInfo in UWP apps, but it can only work with the folders that UWP apps can access by default such as the install directory and local folder etc. Most types in the System.IO namespaces for UWP apps have the similar limitation. While dealing with files or folders in UWP, one important rule is Skip the path: stick to the StorageFile.

You can use a Folder​Picker to let the user choose a folder and then add it to your app's FutureAccessList or MostRecentlyUsedList to keep track of it. You can learn more about using these lists in How to track recently-used files and folders. After this, you will be able to retrieve the StorageFolder from FutureAccessList or MostRecentlyUsedList whenever you want to use it.

Once you have the StorageFolder, you can then use GetFilesAsync() or GetFoldersAsync() method in your Parse instead of DirectoryInfo.GetDirectories or DirectoryInfo.GetFiles method.