public async Task SaveAsync(PhotoFrameSettings settings)
        {
            Preferences.Set(AddressKey, settings.Address);
            await SecureStorage.SetAsync(UserNameKey, settings.Username).ConfigureAwait(false);

            await SecureStorage.SetAsync(PasswordKey, settings.Password).ConfigureAwait(false);

            Preferences.Set(HttpsKey, settings.UseHttps);
            Preferences.Set(UseSmartAlbumKey, settings.UseSmartAlbum);
            Preferences.Set(AlbumNameKey, settings.AlbumName);
            Preferences.Set(AlbumIdKey, settings.AlbumId);
        }
        public async Task <PhotoFrameSettings> LoadAsync()
        {
            var address  = Preferences.Get(AddressKey, null);
            var username = await SecureStorage.GetAsync(UserNameKey).ConfigureAwait(false);

            var password = await SecureStorage.GetAsync(PasswordKey).ConfigureAwait(false);

            if (address == null || username == null || password == null)
            {
                return(null);
            }

            var result = new PhotoFrameSettings(address, username, password);

            result.UseHttps      = Preferences.Get(HttpsKey, false);
            result.UseSmartAlbum = Preferences.Get(UseSmartAlbumKey, true);
            result.AlbumName     = Preferences.Get(AlbumNameKey, null);
            result.AlbumId       = Preferences.Get(AlbumIdKey, null);

            return(result);
        }