I'm developing a sample where Messaging Center send status messeges not coupled from device code to my view models. At this point i used a alert message to notice the event before try in View models.
For it I used a static view instance in my share application constructor (App.xaml) where in view constructor I Subscript the status.
App (shared)
public partial class App : Application
{
#region MasterDetailPage
public static MasterDetailPage MDP;
public static NavigationPage NAV = null;
public static MainView _mainpage;
#endregion
public App ()
{
InitializeComponent();
NAV = new NavigationPage(new StarterView()) { BarBackgroundColor = Color.FromHex("701424"), BarTextColor = Color.White }; ;
MDP = new MasterDetailPage();
MDP.BackgroundColor = Xamarin.Forms.Color.FromHex("701424");
_mainpage = new MainView();
MDP.Master = _mainpage;
MDP.Detail = NAV;
MainPage = MDP;
MainPage.Title = "H2X";
}
(View shared)
public MainView ()
{
InitializeComponent ();
string a="Test";
#region MessegeCenter
MessagingCenter.Subscribe<string,string>("APP", "Message_Received", async (sender,arg) =>
{
string b = a;
a = $"{arg}";
await DisplayAlert("Atenção", a+b, "Ok");
});
#endregion
}
Into the specific platform code (Device - UWP) I create a timer that sends messages after some time instanced in mainpage constructor.
void dispatcherTimer_Tick(object sender, object e)
{
DateTimeOffset time = DateTimeOffset.Now;
TimeSpan span = time - lastTime;
lastTime = time;
//Time since last tick should be very very close to Interval
TimerLog.Text += timesTicked + "\t time since last tick: " + span.ToString() + "\n";
timesTicked++;
if (timesTicked > timesToTick)
{
MessagingCenter.Send<string,string>("APP","Message_Received","MR");
}
}
When I run it, twice alert messages with the same text are opening, but there aren't two subscriptions. The same text give me the information that it was from the same send event.
Where is the problem ? Is there any relationship with my static view ?
Thank you in advance
Guilherme
