// Write file with current date to json file in external download folder
private async Task CreateBackup()
{
string filename = DateTime.Now.ToString("dd-MM-yyyy HH:mm:ss") + ".json";
DatabaseModel dm = new DatabaseModel();
dm.Playlists = await playlistRepository.GetAllPlaylistArrayAsync();
dm.Positions = await positionRepository.GetAllPositionArrayAsync();
dm.SongPlaylists = await songPlaylistRepository.GetAllArrayAsync();
dm.SongPositions = await songPositionRepository.GetAllArrayAsync();
dm.Songs = await songRepository.GetAllSongArrayAsync();
var json = JsonConvert.SerializeObject(dm);
DependencyService.Get <IWirteService>().wirteFile(filename, json);
}