public GroupListPage()
{
InitializeComponent();
// open: Message from login to open default group
MessagingCenter.Subscribe <Group>(this, "open", async group => {
var editPage = new GroupPage(new GroupViewModel(group));
await Navigation.PushAsync(editPage);
});
}
async void GroupTappedAsync(object sender, ItemTappedEventArgs e)
{
var item = e.Item as Group;
var editPage = new GroupPage(new GroupViewModel(item));
await Navigation.PushAsync(editPage);
}