NavigationBar properties not updating - fix

src/Controls/src/Core/NavigationPage/NavigationPageToolbar.cs

@@ -44,10 +44,26 @@ void OnToolbarItemsChanged(object sender, EventArgs e)
 
 		void OnPagePropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
 		{
-			if (_currentPage != sender)
-				return;
-
-			OnPropertyChanged(sender, e);
+			if (e.IsOneOf(NavigationPage.HasNavigationBarProperty,
+				NavigationPage.HasBackButtonProperty,
+				NavigationPage.TitleIconImageSourceProperty,
+				NavigationPage.TitleViewProperty,
+				NavigationPage.IconColorProperty) ||
+				e.IsOneOf(Page.TitleProperty,
+				PlatformConfiguration.AndroidSpecific.AppCompat.NavigationPage.BarHeightProperty,
+				NavigationPage.BarBackgroundColorProperty,
+				NavigationPage.BarBackgroundProperty,
+				NavigationPage.BarTextColorProperty) ||
+				e.IsOneOf(
+					PlatformConfiguration.WindowsSpecific.Page.ToolbarDynamicOverflowEnabledProperty,
+					PlatformConfiguration.WindowsSpecific.Page.ToolbarPlacementProperty))
+			{
+				ApplyChanges(_currentNavigationPage);
+			}
+			else if (_currentPage != sender && sender == _currentNavigationPage && e.Is(NavigationPage.CurrentPageProperty))
+			{
+				ApplyChanges(_currentNavigationPage);
+			}
 		}
 
 		void OnPageAppearing(object sender, EventArgs e)
@@ -247,30 +263,6 @@ void ApplyChanges(NavigationPage navigationPage)
 			DynamicOverflowEnabled = PlatformConfiguration.WindowsSpecific.Page.GetToolbarDynamicOverflowEnabled(_currentPage);
 		}
 
-		void OnPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
-		{
-			if (sender == _currentNavigationPage && e.Is(NavigationPage.CurrentPageProperty))
-			{
-				ApplyChanges(_currentNavigationPage);
-			}
-			else if (e.IsOneOf(NavigationPage.HasNavigationBarProperty,
-				NavigationPage.HasBackButtonProperty,
-				NavigationPage.TitleIconImageSourceProperty,
-				NavigationPage.TitleViewProperty,
-				NavigationPage.IconColorProperty) ||
-				e.IsOneOf(Page.TitleProperty,
-				PlatformConfiguration.AndroidSpecific.AppCompat.NavigationPage.BarHeightProperty,
-				NavigationPage.BarBackgroundColorProperty,
-				NavigationPage.BarBackgroundProperty,
-				NavigationPage.BarTextColorProperty) ||
-				e.IsOneOf(
-					PlatformConfiguration.WindowsSpecific.Page.ToolbarDynamicOverflowEnabledProperty,
-					PlatformConfiguration.WindowsSpecific.Page.ToolbarPlacementProperty))
-			{
-				ApplyChanges(_currentNavigationPage);
-			}
-		}
-
 		Color GetBarTextColor() => _currentNavigationPage?.BarTextColor;
 		Color GetIconColor() => (_currentPage != null) ? NavigationPage.GetIconColor(_currentPage) : null;
 

src/Controls/tests/TestCases.HostApp/Issues/Issues22899.xaml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<TabbedPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue22899">
+    <ContentPage Title="Title">
+        <VerticalStackLayout>
+            <Button 
+                Text="Update title" 
+                AutomationId="button"
+                Clicked="Button_Clicked"/>
+            <Label 
+                Text="Button clicked"
+                AutomationId="label"
+                IsVisible="False"
+                x:Name="label"/>
+        </VerticalStackLayout>
+    </ContentPage>
+</TabbedPage>

src/Controls/tests/TestCases.HostApp/Issues/Issues22899.xaml.cs

@@ -0,0 +1,27 @@
+using System;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	[Issue(IssueTracker.Github, 22899, "Title not updated after OnAppearing for TabbedPage in NavigationPage", PlatformAffected.All)]
+	public class Issue22899NavPage : NavigationPage
+	{
+		public Issue22899NavPage() : base(new Issue22899()){ }
+	}
+
+	public partial class Issue22899 : TabbedPage
+	{
+		public Issue22899()
+		{
+			InitializeComponent();
+		}
+
+		void Button_Clicked(object sender, EventArgs e)
+		{
+			Title = "Title has changed";
+			label.IsVisible = true;
+		}
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue22899.cs

@@ -0,0 +1,25 @@
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+	public class Issue22899 : _IssuesUITest
+	{
+		public override string Issue => "Title not updated after OnAppearing for TabbedPage in NavigationPage";
+
+		public Issue22899(TestDevice device) : base(device) { }
+
+		[Test]
+		[Category(UITestCategories.TabbedPage)]
+		public void Issue22899Test()
+		{
+			_ = App.WaitForElement("button");
+			App.Click("button");
+			_ = App.WaitForElement("label");
+
+	        // The test passes if the text in the navigation bar has changed
+			VerifyScreenshot();
+		}
+	}
+}