refactor message center use to services

src/App/Pages/Lock/BaseLockPage.cs

@@ -4,27 +4,28 @@ using Bit.App.Controls;
 using Bit.App.Resources;
 using Xamarin.Forms;
 using XLabs.Ioc;
+using Bit.App.Abstractions;
 
 namespace Bit.App.Pages
 {
     public class BaseLockPage : ExtendedContentPage
     {
+        private readonly IDeviceActionService _deviceActionService;
+
         public BaseLockPage()
             : base(false, false)
         {
-
             UserDialogs = Resolver.Resolve<IUserDialogs>();
+            AuthService = Resolver.Resolve<IAuthService>();
+            _deviceActionService = Resolver.Resolve<IDeviceActionService>();
         }
 
         protected IUserDialogs UserDialogs { get; set; }
+        protected IAuthService AuthService { get; set; }
 
         protected override bool OnBackButtonPressed()
         {
-            if(Device.RuntimePlatform == Device.Android)
-            {
-                MessagingCenter.Send(Application.Current, "BackgroundApp");
-            }
-
+            _deviceActionService.Background();
             return true;
         }
 
@@ -34,8 +35,7 @@ namespace Bit.App.Pages
             {
                 return;
             }
-
-            MessagingCenter.Send(Application.Current, "Logout", (string)null);
+            AuthService.LogOut();
         }
     }
 }