public static void BindProgressBar(this Activity act, AbstractViewModel vmModel) { vmModel.PropertyChanged += (sender, args) => { if (args.PropertyName != nameof(AbstractViewModel.IsWorking)) { return; } act.SetProgressBarVisibility(vmModel.IsWorking); act.SetProgressBarIndeterminateVisibility(vmModel.IsWorking); act.SetProgressBarIndeterminate(vmModel.IsWorking); }; }