public MainPageViewModel()
{
this.forecastService = new ForecastService();
this.forecastService.OnWeatherReady += UpdateWeather;
this.forecastService.OnForecastsReady += UpdateForecasts;
this.cities = forecastService.GetCities();
FavoredCities = new ObservableCollection <City>(forecastService.GetFavoriteCities());
Forecast = new ObservableCollection <ForecastDTO>();
GetWeatherCommand = new RelayCommand(GetWeather);
AddCityCommand = new RelayCommand(AddCity);
DeleteCityCommand = new RelayCommand(DeleteCity);
SelectForecastCommand = new RelayCommand(SelectForecast);
SearchResults = new ObservableCollection <City>();
SearchText = "";
}