public void Init() { if (_controller.IsAlreadySignIn()) { SetAllVisibilitiesCollapsed(); AfterSignInVisibility = Visibility.Visible; return; } SetAllVisibilitiesCollapsed(); BeforeSignInVisibility = Visibility.Visible; FirstRequestedParams = new ObservableCollection <GetParamViewModel> { new GetParamViewModel("First Name"), new GetParamViewModel("Last Name"), new GetParamViewModel("Email"), new GetParamViewModel("Password", isPassword: true), new GetParamViewModel("Confirm Password", isPassword: true) }; SecondRequestedParams = new ObservableCollection <GetParamViewModel> { new GetParamViewModel("Birth Date- day"), new GetParamViewModel("Birth Date- month"), new GetParamViewModel("Birth Date- year"), new GetParamViewModel("Favorite Genre", getParamOptions: _controller.GetTopGenresNames), new GetParamViewModel("Place", getParamOptions: _controller.GetTopPlacesNames), }; ArtistsCollection = new ObservableCollection <GetParamViewModel> { new GetParamViewModel("Artist Name: ", getParamOptions: _controller.GetTopArtistsNames) }; SongsCollection = new ObservableCollection <GetParamViewModel> { new GetParamViewModel("Song Name: ", getParamOptions: _controller.GetTopSongsNames) }; }