Merge branch '3.0.0' into 3.1.0

.nuspec/Xamarin.Forms.AppLinks.nuspec

@@ -13,10 +13,6 @@
     <description>Add support for deep linking and indexing app content using Xamarin.Forms on the Android Platform</description>
     <copyright>© Microsoft Corporation. All rights reserved.</copyright>
     <dependencies>
-      <group targetFramework="MonoAndroid10">
-        <dependency id="Xamarin.Android.Support.v4" version="[23.3.0]"/>
-        <dependency id="Xamarin.GooglePlayServices.AppIndexing" version="[29.0.0.1]"/>
-      </group>
       <group targetFramework="MonoAndroid71">
         <dependency id="Xamarin.GooglePlayServices.AppIndexing" version="42.1021.1"/>
       </group>

.nuspec/Xamarin.Forms.Maps.nuspec

@@ -16,18 +16,6 @@
       <group>
         <dependency id="Xamarin.Forms" version="$version$"/>
       </group>
-      <group targetFramework="MonoAndroid10">
-        <dependency id="Xamarin.GooglePlayServices.Maps" version="[29.0.0.1]"/>
-        <dependency id="Xamarin.Android.Support.v7.MediaRouter" version="[23.3.0]"/>
-        <dependency id="Xamarin.Android.Support.v7.AppCompat" version="[23.3.0]"/>
-        <dependency id="Xamarin.Forms" version="$version$"/>
-      </group>
-      <group targetFramework="MonoAndroid70">
-        <dependency id="Xamarin.GooglePlayServices.Maps" version="29.0.0.1"/>
-        <dependency id="Xamarin.Android.Support.v7.MediaRouter" version="23.3.0"/>
-        <dependency id="Xamarin.Android.Support.v7.AppCompat" version="23.3.0"/>
-        <dependency id="Xamarin.Forms" version="$version$"/>
-      </group>
       <group targetFramework="MonoAndroid71">
         <dependency id="Xamarin.GooglePlayServices.Maps" version="42.1021.1"/>
         <dependency id="Xamarin.Android.Support.v7.MediaRouter" version="25.4.0.2"/>

.nuspec/Xamarin.Forms.nuspec

@@ -13,20 +13,6 @@
     <description>Build native UIs for iOS, Android, UWP, macOS, Tizen and many more from a single, shared C# codebase</description>
     <copyright>© Microsoft Corporation. All rights reserved.</copyright>
     <dependencies>
-      <group targetFramework="MonoAndroid10">
-        <dependency id="Xamarin.Android.Support.v4" version="[23.3.0]"/>
-        <dependency id="Xamarin.Android.Support.Design" version="[23.3.0]"/>
-        <dependency id="Xamarin.Android.Support.v7.AppCompat" version="[23.3.0]"/>
-        <dependency id="Xamarin.Android.Support.v7.CardView" version="[23.3.0]"/>
-        <dependency id="Xamarin.Android.Support.v7.MediaRouter" version="[23.3.0]"/>
-      </group>
-      <group targetFramework="MonoAndroid70">
-        <dependency id="Xamarin.Android.Support.v4" version="23.3.0"/>
-        <dependency id="Xamarin.Android.Support.Design" version="23.3.0"/>
-        <dependency id="Xamarin.Android.Support.v7.AppCompat" version="23.3.0"/>
-        <dependency id="Xamarin.Android.Support.v7.CardView" version="23.3.0"/>
-        <dependency id="Xamarin.Android.Support.v7.MediaRouter" version="23.3.0"/>
-      </group>
       <group targetFramework="MonoAndroid71">
         <dependency id="Xamarin.Android.Support.v4" version="25.4.0.2"/>
         <dependency id="Xamarin.Android.Support.Design" version="25.4.0.2"/>

Xamarin.Forms.ControlGallery.Android/MainApplication.cs

@@ -1,6 +1,7 @@
 using System;
 
 using Android.App;
+using Android.Content;
 using Android.OS;
 using Android.Runtime;
 using Plugin.CurrentActivity;
@@ -11,7 +12,9 @@ namespace Xamarin.Forms.ControlGallery.Android
     [Application]
     public class MainApplication : global::Android.App.Application, global::Android.App.Application.IActivityLifecycleCallbacks
     {
-        public MainApplication(IntPtr handle, JniHandleOwnership transer)
+		internal static Context ActivityContext { get; private set; }
+
+		public MainApplication(IntPtr handle, JniHandleOwnership transer)
           :base(handle, transer)
         {
         }
@@ -32,32 +35,39 @@ namespace Xamarin.Forms.ControlGallery.Android
         public void OnActivityCreated(Activity activity, Bundle savedInstanceState)
         {
             CrossCurrentActivity.Current.Activity = activity;
-        }
+			ActivityContext = activity;
+		}
 
         public void OnActivityDestroyed(Activity activity)
-        {
-        }
+		{
+			ActivityContext = activity;
+		}
 
         public void OnActivityPaused(Activity activity)
-        {
-        }
+		{
+			ActivityContext = activity;
+		}
 
         public void OnActivityResumed(Activity activity)
         {
             CrossCurrentActivity.Current.Activity = activity;
-        }
+			ActivityContext = activity;
+		}
 
         public void OnActivitySaveInstanceState(Activity activity, Bundle outState)
-        {
-        }
+		{
+			ActivityContext = activity;
+		}
 
         public void OnActivityStarted(Activity activity)
         {
             CrossCurrentActivity.Current.Activity = activity;
-        }
+			ActivityContext = activity;
+		}
 
         public void OnActivityStopped(Activity activity)
-        {
-        }
+		{
+			ActivityContext = activity;
+		}
     }
 }

Xamarin.Forms.ControlGallery.Android/RegistrarValidationService.cs

@@ -0,0 +1,37 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.Android;
+using Xamarin.Forms.Controls;
+
+[assembly: Dependency(typeof(RegistrarValidationService))]
+namespace Xamarin.Forms.ControlGallery.Android
+{
+	public class RegistrarValidationService : IRegistrarValidationService
+	{
+		readonly global::Android.Content.Context _context;
+
+		public RegistrarValidationService()
+		{
+			_context = MainApplication.ActivityContext;
+		}
+
+		public bool Validate(VisualElement element, out string message)
+		{
+			message = "Success";
+
+			if (element == null)
+				return true;
+
+			var renderer = Platform.Android.Platform.CreateRendererWithContext(element, _context);
+
+			if (renderer == null
+				|| renderer.GetType().Name == "DefaultRenderer"
+				)
+			{
+				message = $"Failed to load Android renderer for {element.GetType().Name}";
+				return false;
+			}
+
+			return true;
+		}
+	}
+}

Xamarin.Forms.ControlGallery.Android/SampleNativeControl.cs

@@ -0,0 +1,29 @@
+using Android.Content;
+using Android.Widget;
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.Android;
+using Xamarin.Forms.Controls.Issues.Helpers;
+using Xamarin.Forms.Platform.Android;
+
+[assembly: Dependency(typeof(SampleNativeControl))]
+namespace Xamarin.Forms.ControlGallery.Android
+{
+	public class SampleNativeControl : ISampleNativeControl
+	{
+		readonly Context _context;
+
+		public SampleNativeControl()
+		{
+			_context = MainApplication.ActivityContext;
+		}
+
+		public View View
+		{
+			get
+			{
+				var textView = new TextView(_context) { Text = "Sample Native Control", TextSize = 14 };
+				return textView.ToView();
+			}
+		}
+	}
+}

Xamarin.Forms.ControlGallery.Android/Xamarin.Forms.ControlGallery.Android.csproj

@@ -201,9 +201,11 @@
     <Compile Include="PreApplicationClassActivity.cs" />
     <Compile Include="Properties\MapsKey.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="RegistrarValidationService.cs" />
     <Compile Include="Resources\Resource.Designer.cs" />
     <Compile Include="CustomRenderers.cs" />
     <Compile Include="ColorPicker.cs" />
+    <Compile Include="SampleNativeControl.cs" />
     <Compile Include="StringProvider.cs" />
     <Compile Include="TestCloudService.cs" />
     <Compile Include="_1909CustomRenderer.cs" />
@@ -250,6 +252,10 @@
     <AndroidResource Include="Resources\drawable\cover1.jpg" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\PagesGallery\PagesGallery.Droid\PagesGallery.Droid.csproj">
+      <Project>{5EB6EB6B-A412-4F41-A89B-D7C9AAD237F2}</Project>
+      <Name>PagesGallery.Droid</Name>
+    </ProjectReference>
     <ProjectReference Include="..\Stubs\Xamarin.Forms.Platform.Android\Xamarin.Forms.Platform.Android (Forwarders).csproj">
       <Project>{6e53feb1-1100-46ae-8013-17bba35cc197}</Project>
       <Name>Xamarin.Forms.Platform.Android (Forwarders)</Name>

Xamarin.Forms.ControlGallery.GTK/RegistrarValidationService.cs

@@ -0,0 +1,31 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.GTK;
+using Xamarin.Forms.Controls;
+using Xamarin.Forms.Platform.GTK;
+
+[assembly: Dependency(typeof(RegistrarValidationService))]
+namespace Xamarin.Forms.ControlGallery.GTK
+{
+	public class RegistrarValidationService : IRegistrarValidationService
+	{
+		public bool Validate(VisualElement element, out string message)
+		{
+			message = "Success";
+
+			if (element == null)
+				return true;
+
+			var renderer = Platform.GTK.Platform.CreateRenderer(element);
+
+			if (renderer == null 
+				|| renderer.GetType().Name == "DefaultRenderer"
+				)
+			{
+				message = $"Failed to load proper GTK renderer for {element.GetType().Name}";
+				return false;
+			}
+
+			return true;
+		}
+	}
+}

Xamarin.Forms.ControlGallery.GTK/SampleNativeControl.cs

@@ -0,0 +1,19 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.GTK;
+using Xamarin.Forms.Controls.Issues.Helpers;
+using Xamarin.Forms.Platform.GTK;
+
+[assembly: Dependency(typeof(SampleNativeControl))]
+namespace Xamarin.Forms.ControlGallery.GTK
+{
+	public class SampleNativeControl : ISampleNativeControl
+	{
+		public View View
+		{
+			get
+			{
+				return new Label { Text = "NativeViews not supported on GTK" };
+			}
+		}
+	}
+}

Xamarin.Forms.ControlGallery.GTK/Xamarin.Forms.ControlGallery.GTK.csproj

@@ -94,6 +94,8 @@
     <Compile Include="BasicOpenGLView.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="RegistrarValidationService.cs" />
+    <Compile Include="SampleNativeControl.cs" />
     <Compile Include="StringProvider.cs" />
   </ItemGroup>
   <ItemGroup>

Xamarin.Forms.ControlGallery.MacOS/RegistrarValidationService.cs

@@ -0,0 +1,31 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.MacOS;
+using Xamarin.Forms.Controls;
+using Xamarin.Forms.Platform.MacOS;
+
+[assembly: Dependency(typeof(RegistrarValidationService))]
+namespace Xamarin.Forms.ControlGallery.MacOS
+{
+	public class RegistrarValidationService : IRegistrarValidationService
+	{
+		public bool Validate(VisualElement element, out string message)
+		{
+			message = "Success";
+
+			if (element == null)
+				return true;
+
+			var renderer = Platform.MacOS.Platform.CreateRenderer(element);
+
+			if (renderer == null 
+				|| renderer.GetType().Name == "DefaultRenderer"
+				)
+			{
+				message = $"Failed to load proper MacOS renderer for {element.GetType().Name}";
+				return false;
+			}
+
+			return true;
+		}
+	}
+}

Xamarin.Forms.ControlGallery.MacOS/SampleNativeControl.cs

@@ -0,0 +1,24 @@
+using AppKit;
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.MacOS;
+using Xamarin.Forms.Controls.Issues.Helpers;
+using Xamarin.Forms.Platform.MacOS;
+
+[assembly: Dependency(typeof(SampleNativeControl))]
+namespace Xamarin.Forms.ControlGallery.MacOS
+{
+	public class SampleNativeControl : ISampleNativeControl
+	{
+		public View View
+		{
+			get
+			{
+				var uiLabel = new NSTextField
+				{
+					StringValue = "Sample Native Control"
+				};
+				return uiLabel.ToView();
+			}
+		}
+	}
+}

Xamarin.Forms.ControlGallery.MacOS/Xamarin.Forms.ControlGallery.MacOS.csproj

@@ -105,6 +105,8 @@
     <Compile Include="NativeServices.cs" />
     <Compile Include="BrokenNativeControl.cs" />
     <Compile Include="CustomRenderers.cs" />
+    <Compile Include="RegistrarValidationService.cs" />
+    <Compile Include="SampleNativeControl.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Xamarin.Forms.Controls\Xamarin.Forms.Controls.csproj">

Xamarin.Forms.ControlGallery.Tizen/RegistrarValidationService.cs

@@ -0,0 +1,31 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.Tizen;
+using Xamarin.Forms.Controls;
+using Xamarin.Forms.Platform.Tizen;
+
+[assembly: Dependency(typeof(RegistrarValidationService))]
+namespace Xamarin.Forms.ControlGallery.Tizen
+{
+	public class RegistrarValidationService : IRegistrarValidationService
+	{
+		public bool Validate(VisualElement element, out string message)
+		{
+			message = "Success";
+
+			if (element == null || element is OpenGLView)
+				return true;
+
+			var renderer = Platform.Tizen.Platform.GetOrCreateRenderer(element);
+
+			if (renderer == null 
+				|| renderer.GetType().Name == "DefaultRenderer"
+				)
+			{
+				message = $"Failed to load proper Tizen renderer for {element.GetType().Name}";
+				return false;
+			}
+
+			return true;
+		}
+	}
+}

Xamarin.Forms.ControlGallery.Tizen/SampleNativeControl.cs

@@ -0,0 +1,19 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.Tizen;
+using Xamarin.Forms.Controls.Issues.Helpers;
+using Xamarin.Forms.Platform.Tizen;
+
+[assembly: Dependency(typeof(SampleNativeControl))]
+namespace Xamarin.Forms.ControlGallery.Tizen
+{
+	public class SampleNativeControl : ISampleNativeControl
+	{
+		public View View
+		{
+			get
+			{
+				return new Label { Text = "NativeViews not supported on Tizen" };
+			}
+		}
+	}
+}

Xamarin.Forms.ControlGallery.WPF/RegistrarValidationService.cs

@@ -0,0 +1,31 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.WPF;
+using Xamarin.Forms.Controls;
+using Xamarin.Forms.Platform.WPF;
+
+[assembly: Dependency(typeof(RegistrarValidationService))]
+namespace Xamarin.Forms.ControlGallery.WPF
+{
+	public class RegistrarValidationService : IRegistrarValidationService
+	{
+		public bool Validate(VisualElement element, out string message)
+		{
+			message = "Success";
+
+			if (element == null || element is OpenGLView)
+				return true;
+
+			var renderer = Platform.WPF.Platform.GetOrCreateRenderer(element);
+
+			if (renderer == null 
+				|| renderer.GetType().Name == "DefaultRenderer"
+				)
+			{
+				message = $"Failed to load proper WPF renderer for {element.GetType().Name}";
+				return false;
+			}
+
+			return true;
+		}
+	}
+}

Xamarin.Forms.ControlGallery.WPF/SampleNativeControl.cs

@@ -0,0 +1,19 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.WPF;
+using Xamarin.Forms.Controls.Issues.Helpers;
+using Xamarin.Forms.Platform.WPF;
+
+[assembly: Dependency(typeof(SampleNativeControl))]
+namespace Xamarin.Forms.ControlGallery.WPF
+{
+	public class SampleNativeControl : ISampleNativeControl
+	{
+		public View View
+		{
+			get
+			{
+				return new Label { Text = "NativeViews not supported on WPF" };
+			}
+		}
+	}
+}

Xamarin.Forms.ControlGallery.WPF/Xamarin.Forms.ControlGallery.WPF.csproj

@@ -69,6 +69,8 @@
       <SubType>Designer</SubType>
     </ApplicationDefinition>
     <Compile Include="OpenGLViewApp.cs" />
+    <Compile Include="RegistrarValidationService.cs" />
+    <Compile Include="SampleNativeControl.cs" />
     <Compile Include="StringProvider.cs" />
     <Page Include="MainWindow.xaml">
       <Generator>MSBuild:Compile</Generator>

Xamarin.Forms.ControlGallery.WindowsUniversal/RegistrarValidationService.cs

@@ -0,0 +1,31 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.WindowsUniversal;
+using Xamarin.Forms.Controls;
+using Xamarin.Forms.Platform.UWP;
+
+[assembly: Dependency(typeof(RegistrarValidationService))]
+namespace Xamarin.Forms.ControlGallery.WindowsUniversal
+{
+	public class RegistrarValidationService : IRegistrarValidationService
+	{
+		public bool Validate(VisualElement element, out string message)
+		{
+			message = "Success";
+
+			if (element == null || element is OpenGLView)
+				return true;
+
+			var renderer = Platform.UWP.Platform.CreateRenderer(element);
+
+			if (renderer == null 
+				|| renderer.GetType().Name == "DefaultRenderer"
+				)
+			{
+				message = $"Failed to load proper UWP renderer for {element.GetType().Name}";
+				return false;
+			}
+
+			return true;
+		}
+	}
+}

Xamarin.Forms.ControlGallery.WindowsUniversal/SampleNativeControl.cs

@@ -0,0 +1,29 @@
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Media;
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.WindowsUniversal;
+using Xamarin.Forms.Controls.Issues.Helpers;
+using Xamarin.Forms.Platform.UWP;
+
+[assembly: Dependency(typeof(SampleNativeControl))]
+namespace Xamarin.Forms.ControlGallery.WindowsUniversal
+{
+	public class SampleNativeControl : ISampleNativeControl
+	{
+		public View View
+		{
+			get
+			{
+				var textBlock = new TextBlock
+				{
+					Text = "Sample Native Control",
+					FontSize = 14,
+					FontFamily = new FontFamily("HelveticaNeue"),
+					TextWrapping = TextWrapping.Wrap
+				};
+				return textBlock.ToView();
+			}
+		}
+	}
+}

Xamarin.Forms.ControlGallery.WindowsUniversal/Xamarin.Forms.ControlGallery.WindowsUniversal.csproj

@@ -127,6 +127,8 @@
     <Compile Include="AttachedStateEffectRenderer.cs" />
     <Compile Include="BorderEffect.cs" />
     <Compile Include="DisposePageRenderer.cs" />
+    <Compile Include="RegistrarValidationService.cs" />
+    <Compile Include="SampleNativeControl.cs" />
     <Compile Include="_2489CustomRenderer.cs" />
     <Compile Include="_57114Renderer.cs" />
     <Compile Include="_58406EffectRenderer.cs" />

Xamarin.Forms.ControlGallery.iOS/RegistrarValidationService.cs

@@ -0,0 +1,33 @@
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.iOS;
+using Xamarin.Forms.Controls;
+using Xamarin.Forms.Platform.iOS;
+
+[assembly: Dependency(typeof(RegistrarValidationService))]
+namespace Xamarin.Forms.ControlGallery.iOS
+{
+	public class RegistrarValidationService : IRegistrarValidationService
+	{
+		public bool Validate(VisualElement element, out string message)
+		{
+			message = "Success";
+
+			if (element == null)
+				return true;
+
+			var renderer = Platform.iOS.Platform.CreateRenderer(element);
+
+			if (renderer == null 
+				|| renderer.GetType().Name == "DefaultRenderer"
+				|| (element is MasterDetailPage && Device.Idiom == TargetIdiom.Tablet && !(renderer is TabletMasterDetailRenderer))
+				|| (element is MasterDetailPage && Device.Idiom == TargetIdiom.Phone && !(renderer is PhoneMasterDetailRenderer))
+				)
+			{
+				message = $"Failed to load proper iOS renderer for {element.GetType().Name}";
+				return false;
+			}
+
+			return true;
+		}
+	}
+}

Xamarin.Forms.ControlGallery.iOS/SampleNativeControl.cs

@@ -0,0 +1,27 @@
+using UIKit;
+using Xamarin.Forms;
+using Xamarin.Forms.ControlGallery.iOS;
+using Xamarin.Forms.Controls.Issues.Helpers;
+using Xamarin.Forms.Platform.iOS;
+
+[assembly: Dependency(typeof(SampleNativeControl))]
+namespace Xamarin.Forms.ControlGallery.iOS
+{
+	public class SampleNativeControl : ISampleNativeControl
+	{
+		public View View
+		{
+			get
+			{
+				var uiLabel = new UILabel
+				{
+					MinimumFontSize = 14f,
+					Lines = 0,
+					LineBreakMode = UILineBreakMode.WordWrap,
+					Text = "Sample Native Control",
+				};
+				return uiLabel.ToView();
+			}
+		}
+	}
+}

Xamarin.Forms.ControlGallery.iOS/Xamarin.Forms.ControlGallery.iOS.csproj

@@ -41,6 +41,8 @@
     <MtouchTlsProvider>Default</MtouchTlsProvider>
     <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
     <MtouchFloat32>False</MtouchFloat32>
+    <CodesignKey>iPhone Developer</CodesignKey>
+    <CodesignProvision />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhoneSimulator' ">
     <DebugType>none</DebugType>
@@ -110,6 +112,8 @@
     <Compile Include="Main.cs" />
     <Compile Include="AppDelegate.cs" />
     <Compile Include="PerformanceTrackerRenderer.cs" />
+    <Compile Include="RegistrarValidationService.cs" />
+    <Compile Include="SampleNativeControl.cs" />
     <Compile Include="_2489CustomRenderer.cs" />
     <Compile Include="_57114Renderer.cs" />
     <Compile Include="_58406EffectRenderer.cs" />

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Helpers/ISampleNativeControl.cs

@@ -0,0 +1,11 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Xamarin.Forms.Controls.Issues.Helpers
+{
+	public interface ISampleNativeControl
+	{
+		View View { get; }
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Helpers/ViewHelper.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Xamarin.Forms.Controls.Issues.Helpers
+{
+	public static class ViewHelper
+	{
+		public static List<View> GetAllViews()
+		{
+			var controls = new List<View>
+			{
+				new ActivityIndicator { },
+				new BoxView { },
+				new Button { },
+				new DatePicker { },
+				new Editor { },
+				new Entry { },
+				new Image { },
+				new Label { },
+				new ListView { ItemsSource = Enumerable.Range(0,10), ItemTemplate = new DataTemplate(() => new ViewCell{ View = new View() }) },
+				new ListView { ItemsSource = Enumerable.Range(0,10), ItemTemplate = new DataTemplate(typeof(TextCell)) },
+				new ListView { ItemsSource = Enumerable.Range(0,10), ItemTemplate = new DataTemplate(typeof(ImageCell)) },
+				new ListView { ItemsSource = Enumerable.Range(0,10), ItemTemplate = new DataTemplate(typeof(EntryCell)) },
+				new ListView { ItemsSource = Enumerable.Range(0,10), ItemTemplate = new DataTemplate(typeof(SwitchCell)) },
+				new OpenGLView { },
+				new Picker { },
+				new ProgressBar { },
+				new SearchBar { },
+				new Slider { },
+				new Stepper { },
+				new Switch { },
+				new TableView { },
+				new TimePicker { },
+				GetNativeView()
+			};
+
+			return controls;
+		}
+
+		public static List<Page> GetAllPages()
+		{
+			var controls = new List<Page>
+			{
+				new MasterDetailPage { Master = new Page { Title = "Master" }, Detail = new Page() },
+				new NavigationPage(new Page()),
+				new Page(),
+				new ContentPage(),
+				new CarouselPage(),
+				new TabbedPage(),
+				new TemplatedPage(),
+			};
+
+			return controls;
+		}
+
+		public static View GetNativeView()
+		{
+			View view = null;
+			view = DependencyService.Get<ISampleNativeControl>().View;
+			return view;
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue2653.cs

@@ -0,0 +1,137 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using System.Threading.Tasks;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 2653, "[UWP] Grid insert z-order on UWP broken in Forms 3",
+		PlatformAffected.UWP)]
+	public class Issue2653 : TestContentPage
+	{
+		BoxView bv = null;
+		Grid layout = null;
+		const string ButtonText = "Insert Box View";
+		const string MoveUp = "Move Box View Up";
+		const string MoveDown = "Move Box View Down";
+		const string BoxViewIsOverlappingButton = "Box View Is Overlapping";
+		const string Success = "BoxView Not Overlapping";
+		string instructions = $"Click {ButtonText}. If Box View shows up over me test has failed.";
+		const string TestForButtonClicked = "Test For Clicked";
+
+
+		protected override void Init()
+		{
+			layout = new Grid { BackgroundColor = Color.Red, VerticalOptions = LayoutOptions.FillAndExpand, HorizontalOptions = LayoutOptions.FillAndExpand };
+
+			layout.ColumnDefinitions.Add(new ColumnDefinition() { Width = GridLength.Star });
+			layout.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Star });
+			layout.Children.Add(new Button()
+			{
+				Text = ButtonText,
+				BackgroundColor = Color.Green,
+				Margin = 10,
+				TextColor = Color.White,
+				Command = new Command(() =>
+				{
+					if (!AddBoxView())
+					{
+						layout.Children.Remove(bv);
+					}
+				})
+			});
+
+			this.On<iOS>().SetUseSafeArea(true);
+
+			var labelInstructions = new Label { Text = instructions };
+			
+			Content = new StackLayout()
+			{
+				Children =
+				{
+					labelInstructions,
+					new Button(){ Text = MoveUp, AutomationId = MoveUp, Command = new Command(() =>
+					{
+						AddBoxView();
+						layout.RaiseChild(bv);
+					}),  HeightRequest = 45},
+					new Button(){ Text = MoveDown, AutomationId = MoveDown, Command = new Command(() =>
+					{
+						AddBoxView();
+						layout.LowerChild(bv);
+					}),  HeightRequest = 45},
+					layout,
+					new Button(){ Text = TestForButtonClicked, Command = new Command(() =>
+					{
+						if(!layout.Children.Contains(bv))
+						{
+							labelInstructions.Text = Success;
+						}
+						else
+						{
+							labelInstructions.Text = BoxViewIsOverlappingButton;
+						}
+					}),  HeightRequest = 45}
+				}
+			};
+		}
+
+		bool AddBoxView()
+		{
+			if (bv != null && layout.Children.Contains(bv))
+				return false;
+
+			bv = new BoxView
+			{
+				Color = Color.Purple,
+				WidthRequest = 3000,
+				HeightRequest = 3000,
+				HorizontalOptions = LayoutOptions.Center,
+				VerticalOptions = LayoutOptions.Center
+			};
+
+			layout.Children.Insert(0, bv);
+			return true;
+		}
+
+#if UITEST
+		[Test]
+		public void ZIndexWhenInsertingChildren()
+		{
+			RunningApp.WaitForElement(x => x.Marked(ButtonText));
+			RunningApp.Tap(x => x.Marked(ButtonText));
+			RunningApp.Tap(x => x.Marked(ButtonText));
+			RunningApp.Tap(x => x.Marked(TestForButtonClicked));
+			RunningApp.WaitForElement(x => x.Marked(Success));
+		}
+
+
+		[Test]
+		public void MoveUpAndMoveDown()
+		{
+			RunningApp.WaitForElement(x => x.Marked(MoveUp));
+			RunningApp.Tap(x => x.Marked(ButtonText));
+			RunningApp.Tap(x => x.Marked(TestForButtonClicked));
+			RunningApp.WaitForElement(x => x.Marked(BoxViewIsOverlappingButton));
+
+			RunningApp.Tap(x => x.Marked(MoveUp));
+			RunningApp.Tap(x => x.Marked(MoveDown));
+			RunningApp.Tap(x => x.Marked(ButtonText));
+			RunningApp.Tap(x => x.Marked(TestForButtonClicked));
+			RunningApp.WaitForElement(x => x.Marked(Success));
+		}
+#endif
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue2681.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Text;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 2681, "[UWP] Label inside Listview gets stuck inside infinite loop",
+		PlatformAffected.UWP)]
+	public class Issue2681 : TestNavigationPage
+	{
+		const string NavigateToPage = "Click Me.";
+		protected override void Init()
+		{
+			PushAsync(new ContentPage() { Title = "Freeze Test", Content = new Button() { Text = NavigateToPage, Command = new Command(() => this.PushAsync(new FreezeMe())) } });
+		}
+
+		[Preserve(AllMembers = true)]
+		public partial class FreezeMe : ContentPage
+		{
+			public List<int> Items { get; set; }
+
+			public FreezeMe()
+			{
+				this.BindingContext = this;
+				var lv = new ListView()
+				{
+					Margin = new Thickness(20, 5, 5, 5)
+				};
+
+				lv.ItemTemplate = new DataTemplate(() =>
+				{
+					var label = new Label() { Text = "sassifrass" };
+					label.SetBinding(Label.TextProperty, ".");
+					return new ViewCell() { View = label };
+				});
+
+				lv.SetBinding(ListView.ItemsSourceProperty, "Items");
+
+				this.Content = new ScrollView()
+				{
+					Content = new StackLayout()
+					{
+						Children =
+						{
+							new Label(){ Text = "If page is not frozen this test has passed" },
+							new StackLayout()
+							{
+								Orientation = StackOrientation.Horizontal,
+								Children = {lv  }
+							}
+						}
+					}
+				};
+
+				this.Appearing += (s, e) =>
+				{
+					this.Items = new List<int> { 1, 2, 3 };
+					this.OnPropertyChanged("Items");
+				};
+			}
+		}
+
+#if UITEST
+		[Test]
+		public void ListViewDoesntFreezeApp()
+		{
+			RunningApp.Tap(x => x.Marked(NavigateToPage));
+			RunningApp.WaitForElement("3");
+		}
+#endif
+	}
+}

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

@@ -240,12 +240,15 @@
     <Compile Include="$(MSBuildThisFileDirectory)Effects\AttachedStateEffect.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Effects\AttachedStateEffectList.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)GitHub1878.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Helpers\ISampleNativeControl.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Helpers\ViewHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1677.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1801.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1683.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1705_2.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1396.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1415.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue2653.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue2247.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)GroupListViewHeaderIndexOutOfRange.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue1760.cs" />
@@ -308,6 +311,7 @@
       <DependentUpon>Issue2625.xaml</DependentUpon>
       <SubType>Code</SubType>
     </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)Issue2681.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue2983.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue2963.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue2981.cs" />

Xamarin.Forms.Controls/CoreGallery.cs

@@ -443,6 +443,8 @@ namespace Xamarin.Forms.Controls
 	{
 		public CoreRootPage(Page rootPage, NavigationBehavior navigationBehavior = NavigationBehavior.PushAsync)
 		{
+			ValidateRegistrar();
+
 			IStringProvider stringProvider = DependencyService.Get<IStringProvider>();
 
 			Title = stringProvider.CoreGalleryTitle;
@@ -493,7 +495,23 @@ namespace Xamarin.Forms.Controls
 				}
 			};
 		}
+
+		void ValidateRegistrar()
+		{
+			foreach (var view in Issues.Helpers.ViewHelper.GetAllViews())
+			{
+				if (!DependencyService.Get<IRegistrarValidationService>().Validate(view, out string message))
+					throw new InvalidOperationException(message);
+			}
+
+			foreach (var page in Issues.Helpers.ViewHelper.GetAllPages())
+			{
+				if (!DependencyService.Get<IRegistrarValidationService>().Validate(page, out string message))
+					throw new InvalidOperationException(message);
+			}
+		}
 	}
+
 	[Preserve(AllMembers = true)]
 	public interface IStringProvider
 	{

Xamarin.Forms.Controls/IRegistrarValidationService.cs

@@ -0,0 +1,7 @@
+namespace Xamarin.Forms.Controls
+{
+	public interface IRegistrarValidationService
+	{
+		bool Validate(VisualElement element, out string message);
+	}
+}

Xamarin.Forms.Core/BindingExpression.cs

@@ -337,9 +337,13 @@ namespace Xamarin.Forms
 					}
 				}
 			}
-			else
-				property = sourceType.GetDeclaredProperty(part.Content) ?? sourceType.BaseType?.GetProperty(part.Content);
-
+			else {
+				TypeInfo type = sourceType;
+				while (type != null && property == null) {
+					property = type.GetDeclaredProperty(part.Content);
+					type = type.BaseType?.GetTypeInfo();
+				}
+			}
 			if (property != null)
 			{
 				if (property.CanRead && property.GetMethod.IsPublic && !property.GetMethod.IsStatic)

Xamarin.Forms.Core/Performance.cs

@@ -1,6 +1,7 @@
 using System.ComponentModel;
 using System.Runtime.CompilerServices;
 using System;
+using System.Threading;
 
 namespace Xamarin.Forms.Internals
 {
@@ -15,6 +16,8 @@ namespace Xamarin.Forms.Internals
 	[EditorBrowsable(EditorBrowsableState.Never)]
 	public class Performance
 	{
+		static long Reference;
+
 		public static IPerformanceProvider Provider { get; private set; }
 
 		public static void SetProvider(IPerformanceProvider instance)
@@ -22,7 +25,20 @@ namespace Xamarin.Forms.Internals
 			Provider = instance;
 		}
 
-		public static void Start(string reference, string tag = null, [CallerFilePath] string path = null, [CallerMemberName] string member = null)
+		public static void Start(out string reference, string tag = null, [CallerFilePath] string path = null, [CallerMemberName] string member = null)
+		{
+			if (Provider == null)
+			{
+				reference = String.Empty;
+				return;
+			}
+
+			reference = Interlocked.Increment(ref Reference).ToString();
+			Provider.Start(reference, tag, path, member);
+		}
+
+		public static void Start(string reference, string tag = null, [CallerFilePath] string path = null,
+			[CallerMemberName] string member = null)
 		{
 			Provider?.Start(reference, tag, path, member);
 		}
@@ -46,11 +62,11 @@ namespace Xamarin.Forms.Internals
 
 			public DisposablePerformanceReference(string tag, string path, string member)
 			{
-				_reference = Guid.NewGuid().ToString();
 				_tag = tag;
 				_path = path;
 				_member = member;
-				Start(_reference, _tag, _path, _member);
+				Start(out string reference, _tag, _path, _member);
+				_reference = reference;
 			}
 
 			public void Dispose()
@@ -59,4 +75,4 @@ namespace Xamarin.Forms.Internals
 			}
 		}
 	}
-}
+}

Xamarin.Forms.Platform.Android/AppCompat/Platform.cs

@@ -165,8 +165,7 @@ namespace Xamarin.Forms.Platform.Android.AppCompat
 
 		SizeRequest IPlatform.GetNativeSize(VisualElement view, double widthConstraint, double heightConstraint)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			// FIXME: potential crash
 			IVisualElementRenderer visualElementRenderer = Android.Platform.GetRenderer(view);

Xamarin.Forms.Platform.Android/Cells/CellRenderer.cs

@@ -23,8 +23,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		public AView GetCell(Cell item, AView convertView, ViewGroup parent, Context context)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 			
 			Cell = item;
 			Cell.PropertyChanged -= PropertyChangedHandler;
@@ -69,8 +68,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		protected virtual AView GetCellCore(Cell item, AView convertView, ViewGroup parent, Context context)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference, "GetCellCore");
+			Performance.Start(out string reference, "GetCellCore");
 
 			LayoutInflater inflater = LayoutInflater.FromContext(context);
 			const int type = global::Android.Resource.Layout.SimpleListItem1;

Xamarin.Forms.Platform.Android/Cells/ViewCellRenderer.cs

@@ -12,8 +12,7 @@ namespace Xamarin.Forms.Platform.Android
 	{
 		protected override AView GetCellCore(Cell item, AView convertView, ViewGroup parent, Context context)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference, "GetCellCore");
+			Performance.Start(out string reference, "GetCellCore");
 			var cell = (ViewCell)item;
 
 			var container = convertView as ViewCellContainer;
@@ -150,9 +149,7 @@ namespace Xamarin.Forms.Platform.Android
 
 			public void Update(ViewCell cell)
 			{
-				var reference = Guid.NewGuid().ToString();
-				Performance.Start(reference);
-
+				Performance.Start(out string reference);
 				var renderer = GetChildAt(0) as IVisualElementRenderer;
 				var viewHandlerType = Registrar.Registered.GetHandlerTypeForObject(cell.View) ?? typeof(Platform.DefaultRenderer);
 				var reflectableType = renderer as System.Reflection.IReflectableType;
@@ -211,8 +208,7 @@ namespace Xamarin.Forms.Platform.Android
 
 			protected override void OnLayout(bool changed, int l, int t, int r, int b)
 			{
-				var reference = Guid.NewGuid().ToString();
-				Performance.Start(reference);
+				Performance.Start(out string reference);
 
 				double width = Context.FromPixels(r - l);
 				double height = Context.FromPixels(b - t);
@@ -227,8 +223,7 @@ namespace Xamarin.Forms.Platform.Android
 
 			protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
 			{
-				var reference = Guid.NewGuid().ToString();
-				Performance.Start(reference);
+				Performance.Start(out string reference);
 
 				int width = MeasureSpec.GetSize(widthMeasureSpec);
 				int height;

Xamarin.Forms.Platform.Android/FastRenderers/ButtonRenderer.cs

@@ -122,8 +122,7 @@ namespace Xamarin.Forms.Platform.Android.FastRenderers
 			VisualElement oldElement = Button;
 			Button = (Button)element;
 
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			if (oldElement != null)
 			{

Xamarin.Forms.Platform.Android/FastRenderers/ImageRenderer.cs

@@ -112,8 +112,7 @@ namespace Xamarin.Forms.Platform.Android.FastRenderers
 			Image oldElement = _element;
 			_element = image;
 
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			if (oldElement != null)
 				oldElement.PropertyChanged -= OnElementPropertyChanged;

Xamarin.Forms.Platform.Android/Platform.cs

@@ -1232,8 +1232,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		SizeRequest IPlatform.GetNativeSize(VisualElement view, double widthConstraint, double heightConstraint)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			// FIXME: potential crash
 			IVisualElementRenderer visualElementRenderer = GetRenderer(view);

Xamarin.Forms.Platform.Android/Renderers/ListViewAdapter.cs

@@ -62,7 +62,7 @@ namespace Xamarin.Forms.Platform.Android
 			realListView.OnItemLongClickListener = this;
 
 			var platform = _listView.Platform;
-			if (platform.GetType() == typeof(AppCompat.Platform))
+			if (platform?.GetType() == typeof(AppCompat.Platform))
 				MessagingCenter.Subscribe<AppCompat.Platform>(this, AppCompat.Platform.CloseContextActionsSignalName, p => CloseContextActions());
 			else
 				MessagingCenter.Subscribe<Platform>(this, Platform.CloseContextActionsSignalName, p => CloseContextActions());
@@ -194,8 +194,7 @@ namespace Xamarin.Forms.Platform.Android
 		{
 			Cell cell = null;
 
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			ListViewCachingStrategy cachingStrategy = Controller.CachingStrategy;
 			var nextCellIsHeader = false;

Xamarin.Forms.Platform.Android/VisualElementPackager.cs

@@ -89,8 +89,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		void AddChild(VisualElement view, IVisualElementRenderer oldRenderer = null, RendererPool pool = null, bool sameChildren = false)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			if (CompressedLayout.GetIsHeadless(view))
 			{
@@ -165,8 +164,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		void OnChildRemoved(object sender, ElementEventArgs e)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 			var view = e.Element as VisualElement;
 			if (view != null)
 				RemoveChild(view);
@@ -203,8 +201,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		void SetElement(VisualElement oldElement, VisualElement newElement)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			var sameChildrenTypes = false;
 

Xamarin.Forms.Platform.Android/VisualElementRenderer.cs

@@ -130,8 +130,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		public void UpdateLayout()
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 			Tracker?.UpdateLayout();
 			Performance.Stop(reference);
 		}

Xamarin.Forms.Platform.Android/VisualElementTracker.cs

@@ -301,8 +301,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		void UpdateNativeView(object sender, EventArgs e)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			VisualElement view = _renderer.Element;
 			AView aview = _renderer.View;
@@ -328,8 +327,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		void UpdateOpacity()
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			VisualElement view = _renderer.Element;
 			AView aview = _renderer.View;

Xamarin.Forms.Platform.UAP/ListViewRenderer.cs

@@ -88,7 +88,7 @@ namespace Xamarin.Forms.Platform.UWP
 					new CollectionViewSource { Source = Element.ItemsSource, IsSourceGrouped = Element.IsGroupingEnabled };
 			}
 
-			List.UpdateLayout();
+			Device.BeginInvokeOnMainThread(() => List.UpdateLayout());
 		}
 
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)

Xamarin.Forms.Platform.UAP/VisualElementPackager.cs

@@ -15,7 +15,6 @@ namespace Xamarin.Forms.Platform.UWP
 		readonly int _rowSpan;
 		bool _disposed;
 		bool _isLoaded;
-		bool _isZChanged;
 
 		public VisualElementPackager(IVisualElementRenderer renderer)
 		{
@@ -101,17 +100,10 @@ namespace Xamarin.Forms.Platform.UWP
 				IVisualElementRenderer childRenderer = Platform.GetRenderer(child);
 
 				if (childRenderer == null)
-				{
 					continue;
-				}
 
 				if (Canvas.GetZIndex(childRenderer.ContainerElement) != (z + 1))
-				{
-					if (!_isZChanged)
-						_isZChanged = true;
-
 					Canvas.SetZIndex(childRenderer.ContainerElement, z + 1);
-				}
 			}
 		}
 
@@ -136,7 +128,7 @@ namespace Xamarin.Forms.Platform.UWP
 
 			_panel.Children.Add(childRenderer.ContainerElement);
 
-			if (_isZChanged)
+			if (ElementController.LogicalChildren[ElementController.LogicalChildren.Count - 1] != view)
 				EnsureZIndex();
 		}
 

Xamarin.Forms.Platform.iOS/Cells/CellRenderer.cs

@@ -12,8 +12,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 		public virtual UITableViewCell GetCell(Cell item, UITableViewCell reusableCell, UITableView tv)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			var tvc = reusableCell as CellTableViewCell ?? new CellTableViewCell(UITableViewCellStyle.Default, item.GetType().FullName);
 

Xamarin.Forms.Platform.iOS/Cells/ViewCellRenderer.cs

@@ -11,8 +11,7 @@ namespace Xamarin.Forms.Platform.iOS
 	{
 		public override UITableViewCell GetCell(Cell item, UITableViewCell reusableCell, UITableView tv)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			var viewCell = (ViewCell)item;
 
@@ -77,8 +76,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 			public override void LayoutSubviews()
 			{
-				var reference = Guid.NewGuid().ToString();
-				Performance.Start(reference);
+				Performance.Start(out string reference);
 
 				//This sets the content views frame.
 				base.LayoutSubviews();
@@ -107,8 +105,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 			public override SizeF SizeThatFits(SizeF size)
 			{
-				var reference = Guid.NewGuid().ToString();
-				Performance.Start(reference);
+				Performance.Start(out string reference);
 
 				IVisualElementRenderer renderer;
 				if (!_rendererRef.TryGetTarget(out renderer))
@@ -167,8 +164,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 			void UpdateCell(ViewCell cell)
 			{
-				var reference = Guid.NewGuid().ToString();
-				Performance.Start(reference);
+				Performance.Start(out string reference);
 
 				if (_viewCell != null)
 					Device.BeginInvokeOnMainThread(_viewCell.SendDisappearing);

Xamarin.Forms.Platform.iOS/Platform.cs

@@ -182,8 +182,7 @@ namespace Xamarin.Forms.Platform.iOS
 
 		SizeRequest IPlatform.GetNativeSize(VisualElement view, double widthConstraint, double heightConstraint)
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			var renderView = GetRenderer(view);
 			if (renderView == null || renderView.NativeView == null)

Xamarin.Forms.Platform.iOS/Properties/AssemblyInfo.cs

@@ -42,7 +42,6 @@ using UIKit;
 [assembly: ExportRenderer(typeof(NavigationMenu), typeof(NavigationMenuRenderer))]
 [assembly: ExportRenderer(typeof(ListView), typeof(ListViewRenderer))]
 [assembly: ExportRenderer(typeof(OpenGLView), typeof(OpenGLViewRenderer))]
-[assembly: ExportRenderer(typeof(NativeViewWrapper), typeof(NativeViewWrapperRenderer))]
 [assembly: ExportRenderer(typeof(TabbedPage), typeof(TabbedRenderer))]
 [assembly: ExportRenderer(typeof(NavigationPage), typeof(NavigationRenderer))]
 [assembly: ExportRenderer(typeof(CarouselPage), typeof(CarouselPageRenderer))]
@@ -51,6 +50,7 @@ using UIKit;
 #endif
 
 [assembly: ExportRenderer(typeof(MasterDetailPage), typeof(TabletMasterDetailRenderer), UIUserInterfaceIdiom.Pad)]
+[assembly: ExportRenderer(typeof(NativeViewWrapper), typeof(NativeViewWrapperRenderer))]
 
 [assembly: ExportCell(typeof(Cell), typeof(CellRenderer))]
 [assembly: ExportCell(typeof(ImageCell), typeof(ImageCellRenderer))]

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

@@ -911,8 +911,7 @@ namespace Xamarin.Forms.Platform.iOS
 				Cell cell;
 				UITableViewCell nativeCell;
 
-				var reference = Guid.NewGuid().ToString();
-				Performance.Start(reference);
+				Performance.Start(out string reference);
 
 				var cachingStrategy = List.CachingStrategy;
 				if (cachingStrategy == ListViewCachingStrategy.RetainElement)

Xamarin.Forms.Platform.iOS/VisualElementPackager.cs

@@ -85,8 +85,7 @@ namespace Xamarin.Forms.Platform.MacOS
 		{
 			if (_isDisposed)
 				return;
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 			if (CompressedLayout.GetIsHeadless(view))
 			{
 				var packager = new VisualElementPackager(Renderer, view);
@@ -173,8 +172,7 @@ namespace Xamarin.Forms.Platform.MacOS
 			if (oldElement == newElement)
 				return;
 
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			_element = newElement;
 

Xamarin.Forms.Platform.iOS/VisualElementRenderer.cs

@@ -155,8 +155,7 @@ namespace Xamarin.Forms.Platform.MacOS
 			var oldElement = Element;
 			Element = element;
 
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			if (oldElement != null)
 				oldElement.PropertyChanged -= _propertyChangedHandler;

Xamarin.Forms.Platform.iOS/VisualElementTracker.cs

@@ -300,8 +300,7 @@ namespace Xamarin.Forms.Platform.MacOS
 
 		void UpdateNativeControl()
 		{
-			var reference = Guid.NewGuid().ToString();
-			Performance.Start(reference);
+			Performance.Start(out string reference);
 
 			if (_disposed)
 				return;

Xamarin.Forms.Xaml.UnitTests/Issues/Gh2632.xaml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<local:Gh2632Base xmlns="http://xamarin.com/schemas/2014/forms"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Xamarin.Forms.Xaml.UnitTests.Gh2632"
+             xmlns:local="clr-namespace:Xamarin.Forms.Xaml.UnitTests"
+             x:Name="Page">
+	<Label Text="{Binding BindingContext.Foo, Source={x:Reference Page}}" />
+</local:Gh2632Base>

Xamarin.Forms.Xaml.UnitTests/Issues/Gh2632.xaml.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using NUnit.Framework;
+using Xamarin.Forms;
+using Xamarin.Forms.Core.UnitTests;
+
+namespace Xamarin.Forms.Xaml.UnitTests
+{
+	public class Gh2632Base : ContentPage
+	{
+		public new Gh2632Context BindingContext {
+			get => base.BindingContext as Gh2632Context;
+			set => base.BindingContext = value;
+		}
+
+		public class Gh2632Context
+		{
+			public string Foo { get; set; }
+		}
+	}
+
+	public partial class Gh2632 : Gh2632Base
+	{
+		public Gh2632()
+		{
+			InitializeComponent();
+		}
+
+		public Gh2632(bool useCompiledXaml)
+		{
+			//this stub will be replaced at compile time
+		}
+
+
+		[TestFixture]
+		class Tests
+		{
+
+			[SetUp]
+			public void Setup()
+			{
+				Device.PlatformServices = new MockPlatformServices();
+			}
+
+			[TearDown]
+			public void TearDown()
+			{
+				Device.PlatformServices = null;
+			}
+
+			[TestCase(false), TestCase(true)]
+			public void BindingDoesNotThrowOnRedefinedProperty(bool useCompiledXaml)
+			{
+				var layout = new Gh2632(useCompiledXaml);
+				layout.BindingContext = new Gh2632Base.Gh2632Context { Foo = "foo" };
+			}
+		}
+	}
+}

Xamarin.Forms.Xaml.UnitTests/Xamarin.Forms.Xaml.UnitTests.csproj

@@ -606,6 +606,9 @@
     <Compile Include="Issues\Gh2517.xaml.cs">
       <DependentUpon>Gh2517.xaml</DependentUpon>
     </Compile>
+    <Compile Include="Issues\Gh2632.xaml.cs">
+      <DependentUpon>Gh2632.xaml</DependentUpon>
+    </Compile>
     <Compile Include="Issues\Gh2549.xaml.cs">
       <DependentUpon>Gh2549.xaml</DependentUpon>
     </Compile>
@@ -1108,6 +1111,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="Issues\Gh2632.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
     <EmbeddedResource Include="Issues\Gh2549.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>

Xamarin.Forms.Xaml/ApplyPropertiesVisitor.cs

@@ -544,6 +544,7 @@ namespace Xamarin.Forms.Xaml
 			value = null;
 			var elementType = element.GetType();
 			PropertyInfo propertyInfo = null;
+#if NETSTANDARD1_0
 			try {
 				propertyInfo = elementType.GetRuntimeProperty(localName);
 			} catch (AmbiguousMatchException) {
@@ -553,6 +554,12 @@ namespace Xamarin.Forms.Xaml
 						propertyInfo = property;
 				}
 			}
+#else
+			while (elementType != null && propertyInfo == null) {
+				propertyInfo = elementType.GetProperty(localName, BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.DeclaredOnly);
+				elementType = elementType.BaseType;
+			}
+#endif
 			MethodInfo getter;
 			targetProperty = propertyInfo;
 			if (propertyInfo == null || !propertyInfo.CanRead || (getter = propertyInfo.GetMethod) == null)