ArcGISPortalViewer.ViewModel.MainViewModel.ExecuteSignOutCommand C# (CSharp) Method

        private async void ExecuteSignOutCommand()
        {
            Windows.UI.Popups.MessageDialog dialog = new Windows.UI.Popups.MessageDialog(string.Format("Do you want to sign out from {0}?", string.IsNullOrEmpty(PortalService.CurrentPortalService.OrganizationName)? "ArcGIS.com" : PortalService.CurrentPortalService.OrganizationName));
            dialog.Commands.Add(new Windows.UI.Popups.UICommand("Sign out", (a) => 
            { 
                // clear all observable collections
                ClearAllCollections();

                // signal changes on PortalService properties
                RaisePropertyChanged(PortalServicePropertyName);                

                // sign out the current portal connection 
                Messenger.Default.Send<ChangeSignOutMessage>(new ChangeSignOutMessage() { });
            }));
            dialog.Commands.Add(new Windows.UI.Popups.UICommand("Cancel", (a) => { }));
            await dialog.ShowAsync();
        }