private PlayListViewModel()
        {
            Add        = new Command.AddPlaylistCommand(AddPlaylist);
            Delete     = new Command.DeletePlaylistCommand(RemovePlaylist);
            AddItem    = new Command.AddPlaylistItemCommand(AddPlaylistItem);
            DeleteItem = new Command.DeletePlaylistItemCommand(DeletePlaylistItem);
            UpItem     = new Command.UpPlaylistItemCommand(UpPlaylistItem);
            DownItem   = new Command.DownPlaylistItemCommand(DownPlaylistItem);

            LoadData();
        }
        private PlayListViewModel()
        {
            Add = new Command.AddPlaylistCommand(AddPlaylist);
            Delete = new Command.DeletePlaylistCommand(RemovePlaylist);
            AddItem = new Command.AddPlaylistItemCommand(AddPlaylistItem);
            DeleteItem = new Command.DeletePlaylistItemCommand(DeletePlaylistItem);
            UpItem = new Command.UpPlaylistItemCommand(UpPlaylistItem);
            DownItem = new Command.DownPlaylistItemCommand(DownPlaylistItem);

            LoadData();
        }