} //Binable command to fetch a saying
public MainPageViewModel(SayingsAbstractModel WithModel)
{
DataModel = WithModel;
//Hook up FetchNextSayingCommand property
FetchNextSayingCommand = new Command(execute: async() => await DoFetchNextMessageCommand(),
canExecute: () => ButtonEnabled);
//Hook up event handler for changes in the model
DataModel.PropertyChanged += OnPropertyChanged;
}
} //Binable command to fetch a saying
public MainPageViewModel(SayingsAbstractModel WithModel, IMainPageViewHelper pvh)
{
//Reference back to ViewHelper (typically the View, but might be a unit test framework)
MainPageViewHelper = pvh;
//Set chosen data model (this may different, depending if instantiated by the view or a unit test framework
DataModel = WithModel;
//Hook up event handler for changes in the model
DataModel.PropertyChanged += OnPropertyChanged;
//Hook up button command (typically created by the view as Command is part of Xamarin.Forms)
FetchNextSayingCommand = MainPageViewHelper.CreateConcreteCommand(execute: async() => await DoFetchNextMessageCommand(),
canExecute: () => ButtonEnabled);
}