[iOS] Fix extra tab icon appearing in iOS for TabbedPage (was #448)

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla45284.xaml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             Title="Repro"
+             ItemsSource="{Binding Tabs}"
+             x:Class="Xamarin.Forms.Controls.Issues.Bugzilla45284">
+  <TabbedPage.ItemTemplate>
+    <DataTemplate>
+      <ContentPage Title="{Binding Title}" Icon="{Binding Icon}">
+        <Label>Hello</Label>
+      </ContentPage>
+    </DataTemplate>
+  </TabbedPage.ItemTemplate>
+</TabbedPage>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla45284.xaml.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using Xamarin.Forms;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if APP
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 45284, "[iOS10] Extra tab icons display in iOS when binding Title on TabbedPage", PlatformAffected.iOS)]
+	public partial class Bugzilla45284 : TabbedPage
+	{
+		public Bugzilla45284()
+		{
+			var model = new Bugzilla45284Model();
+			InitializeComponent();
+			BindingContext = model;
+			model.Change();
+		}
+	}
+
+	public class Bugzilla45284Model : INotifyPropertyChanged
+	{
+		public List<Bugzilla45284TabModel> Tabs => new List<Bugzilla45284TabModel> { 
+			new Bugzilla45284TabModel(),
+			new Bugzilla45284TabModel(),
+			new Bugzilla45284TabModel(),
+			new Bugzilla45284TabModel(),
+			new Bugzilla45284TabModel(),
+			new Bugzilla45284TabModel(),
+			new Bugzilla45284TabModel(),
+		};
+
+		public event PropertyChangedEventHandler PropertyChanged;
+		public void Change()
+		{
+			PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Tabs)));
+		}
+	}
+
+	public class Bugzilla45284TabModel
+	{
+		public string Title { get; set; } = "Title";
+		public string Icon { get; set; } = "bank.png";
+	}
+#endif
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -484,6 +484,9 @@
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla35736.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla48158.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla45926.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Bugzilla45284.xaml.cs">
+      <DependentUpon>Bugzilla45284.xaml</DependentUpon>
+    </Compile>
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Bugzilla22229.xaml">
@@ -593,6 +596,9 @@
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Bugzilla39378.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="$(MSBuildThisFileDirectory)Bugzilla45284.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Bugzilla27417Xaml.xaml">

Xamarin.Forms.Platform.iOS/Forms.cs

@@ -26,6 +26,8 @@ public static class Forms
 
 		static bool? s_isiOS9OrNewer;
 
+		static bool? s_isiOS10OrNewer;
+
 		static Forms()
 		{
 			if (nevertrue)
@@ -44,6 +46,16 @@ internal static bool IsiOS9OrNewer
 			}
 		}
 
+		internal static bool IsiOS10OrNewer
+		{
+			get
+			{
+				if (!s_isiOS10OrNewer.HasValue)
+					s_isiOS10OrNewer = UIDevice.CurrentDevice.CheckSystemVersion(10, 0);
+				return s_isiOS10OrNewer.Value;
+			}
+		}
+
 		public static void Init()
 		{
 			if (IsInitialized)

Xamarin.Forms.Platform.iOS/Renderers/TabbedRenderer.cs

@@ -171,7 +171,9 @@ void HandleFinishedCustomizingViewControllers(object sender, UITabBarCustomizeCh
 
 		void OnPagePropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
-			if (e.PropertyName == Page.TitleProperty.PropertyName)
+			// Setting TabBarItem.Title in iOS 10 causes rendering bugs
+			// Work around this by creating a new UITabBarItem on each change
+			if (e.PropertyName == Page.TitleProperty.PropertyName && !Forms.IsiOS10OrNewer)
 			{
 				var page = (Page)sender;
 				var renderer = Platform.GetRenderer(page);
@@ -181,7 +183,7 @@ void OnPagePropertyChanged(object sender, PropertyChangedEventArgs e)
 				if (renderer.ViewController.TabBarItem != null)
 					renderer.ViewController.TabBarItem.Title = page.Title;
 			}
-			else if (e.PropertyName == Page.IconProperty.PropertyName)
+			else if (e.PropertyName == Page.IconProperty.PropertyName || e.PropertyName == Page.TitleProperty.PropertyName && Forms.IsiOS10OrNewer)
 			{
 				var page = (Page)sender;