Fix missing iOS navigation events and removes duplicate page (dis)appearing events

Author: albyrock87

src/Sentry.Maui/Internal/MauiEventsBinder.cs

@@ -34,7 +34,16 @@ public void HandleApplicationEvents(Application application, bool bind = true)
     {
         if (bind)
         {
-            // Attach element events to all descendents as they are added to the application.
+            // Attach element events to all existing descendants (skip the application itself)
+            foreach (var descendant in application.GetVisualTreeDescendants().Skip(1))
+            {
+                if (descendant is VisualElement element)
+                {
+                    OnApplicationOnDescendantAdded(application, new ElementEventArgs(element));
+                }
+            }
+
+            // Attach element events to all descendants as they are added to the application.
             application.DescendantAdded += OnApplicationOnDescendantAdded;
             application.DescendantRemoved += OnApplicationOnDescendantRemoved;
 

test/Sentry.Maui.Tests/MauiEventsBinderTests.Application.cs

@@ -145,6 +145,34 @@ public void Application_UnbindModalEvents_DoesNotAddBreadcrumb(string eventName,
         Assert.Single(_fixture.Scope.Breadcrumbs);
     }
 
+    [Fact]
+    public void Application_HandleApplicationEvents_TracksExistingDescendants()
+    {
+        // Arrange
+        var application = MockApplication.Create();
+        var element = new MockVisualElement("element");
+        application.MainPage = new ContentPage
+        {
+            Content = new VerticalStackLayout
+            {
+                element
+            }
+        };
+
+        _fixture.Binder.HandleApplicationEvents(application);
+
+        // Act
+        element.RaiseEvent(nameof(VisualElement.Focused), new FocusEventArgs(element, true));
+
+        // Assert
+        var crumb = Assert.Single(_fixture.Scope.Breadcrumbs);
+        Assert.Equal($"{nameof(MockVisualElement)}.{nameof(VisualElement.Focused)}", crumb.Message);
+        Assert.Equal(BreadcrumbLevel.Info, crumb.Level);
+        Assert.Equal(MauiEventsBinder.SystemType, crumb.Type);
+        Assert.Equal(MauiEventsBinder.RenderingCategory, crumb.Category);
+        crumb.Data.Should().Contain($"{nameof(MockVisualElement)}.Name", "element");
+    }
+
     public static IEnumerable<object[]> ApplicationModalEventsData
     {
         get