protected override void OnNavigatedTo(NavigationEventArgs e)
{
parameters = (Dictionary <string, ViewModelBase>)e.Parameter;
TopicViewModel topicVm = (TopicViewModel)parameters["topicVm"];
TopicTitle = topicVm.TopicTitle;
//TopicViewModel topicVm = (TopicViewModel) e.Parameter;
MessageViewModel messageVM = new MessageViewModel();
DataContext = messageVM;
SystemNavigationManager.GetForCurrentView().BackRequested += MainPage_BackRequested;
//ObservableCollection<ViewModelBase> ret = await ((MessageViewModel)DataContext).GetListMessage(topicVm.TopicId);
messageVM.GetListMessage(topicVm.TopicId);
}
