public MainPageViewModel() { var presenter = (Bxf.IPresenter)Bxf.Shell.Instance; presenter.OnShowError += (message, caption) => { MessageBox.Show(message, caption, MessageBoxButton.OK); }; presenter.OnShowStatus += (status) => { }; presenter.OnShowView += (view, region) => { if (region == "Content") { MainContent.Add(view.ViewInstance); while (MainContent.Count > 1) { MainContent.RemoveAt(0); } } }; if (!DesignerProperties.IsInDesignTool) { ListPersons(); } }