Fix for issue xamarin#7671

neolithos · May 25, 2020 · b7e17e9 · b7e17e9
1 parent 54e23c4
commit b7e17e9
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Showing 4 changed files with 91 additions and 20 deletions.
diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue7671.xaml b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue7671.xaml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:d="http://xamarin.com/schemas/2014/forms/design"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             mc:Ignorable="d"
+             x:Class="Xamarin.Forms.Controls.Issues.Issue7671">
+    <ContentPage.Content>
+        <StackLayout>
+            <Label Text="Welcome to Xamarin.Forms!"
+                VerticalOptions="CenterAndExpand" 
+                HorizontalOptions="CenterAndExpand" />
+        </StackLayout>
+    </ContentPage.Content>
+    <ContentPage.ControlTemplate>
+        <ControlTemplate>
+            <Grid>
+                <Grid.RowDefinitions>
+                    <RowDefinition Height="30" />
+                    <RowDefinition />
+                </Grid.RowDefinitions>
+
+                <Frame BackgroundColor="Green">
+                    <Label Grid.Row="0" Text="I am the template." />
+                </Frame>
+                <ContentPresenter Grid.Row="1" />
+            </Grid>
+        </ControlTemplate>
+    </ContentPage.ControlTemplate>
+</ContentPage>
diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue7671.xaml.cs b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue7671.xaml.cs
@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using Xamarin.Forms;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using Xamarin.Forms.Xaml;
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.None, 7671, "Automate GC checks of picker disposals", PlatformAffected.WPF)]
+	[XamlCompilation(XamlCompilationOptions.Compile)]
+	public partial class Issue7671 : ContentPage
+	{
+		public Issue7671()
+		{
+			InitializeComponent();
+		}
+	}
+}
diff --git a/...ssues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems b/...ssues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
@@ -159,6 +159,10 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue7519Xaml.xaml.cs">
       <SubType>Code</SubType>
     </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)Issue7671.xaml.cs">
+      <DependentUpon>Issue7671.xaml</DependentUpon>
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Issue7700.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue7758.xaml.cs">
       <SubType>Code</SubType>
@@ -1929,6 +1933,13 @@
       <Generator>MSBuild:Compile</Generator>
     </EmbeddedResource>
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue7671.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </EmbeddedResource>
+  </ItemGroup>
+</Project>
   <ItemGroup>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue7048.xaml">
       <SubType>Designer</SubType>

diff --git a/Xamarin.Forms.Platform.WPF/Renderers/PageRenderer.cs b/Xamarin.Forms.Platform.WPF/Renderers/PageRenderer.cs
@@ -1,49 +1,55 @@
 using System.ComponentModel;
+using System.Linq;
 using Xamarin.Forms.Platform.WPF.Controls;
 
 namespace Xamarin.Forms.Platform.WPF
 {
 	public class PageRenderer : VisualPageRenderer<Page, FormsContentPage>
 	{
-		VisualElement _currentView;
+		VisualElement _currentView = null;
 
 		protected override void OnElementChanged(ElementChangedEventArgs<Page> e)
 		{
 			if (e.NewElement != null)
 			{
-				if (Control == null) // construct and SetNativeControl and suscribe control event
-				{
+				if (Control == null)
 					SetNativeControl(new FormsContentPage());
-				}
 
-				// Update control property 
 				UpdateContent();
 			}
-
 			base.OnElementChanged(e);
-		}
-		
+		} // proc OnElementChanged
+
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
 			base.OnElementPropertyChanged(sender, e);
-
-			if(e.PropertyName == ContentPage.ContentProperty.PropertyName)
+			if (e.PropertyName == ContentPage.ContentProperty.PropertyName
+				|| e.PropertyName == TemplatedPage.ControlTemplateProperty.PropertyName)
+			{
 				UpdateContent();
-		}
+			}
+		} // proc OnElementPropertyChanged
+
 
-		void UpdateContent()
+		private void UpdateContent()
 		{
-			ContentPage page = Element as ContentPage;
-			if (page != null)
+			if (_currentView != null) // destroy current view
 			{
-				if (_currentView != null)
-				{
-					_currentView.Cleanup(); // cleanup old view
-				}
+				_currentView?.Cleanup();
+				_currentView = null;
+			}
 
-				_currentView = page.Content;
-				Control.Content = _currentView != null ? Platform.GetOrCreateRenderer(_currentView).GetNativeElement() : null;
+			// create new view based on the first children, not content
+			if (Element is IElementController page)
+			{
+				_currentView = page.LogicalChildren.OfType<VisualElement>().FirstOrDefault();
+				if (_currentView != null)
+					Control.Content = Platform.GetOrCreateRenderer(_currentView).GetNativeElement();
+				else
+					Control.Content = null;
 			}
+			else
+				Control.Content = null;
 		}
 	}
 }