[UWP] Delay RequestRefresh until Loaded (#8190)

fixes #8186

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue8186.cs

@@ -0,0 +1,80 @@
+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;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 8186, "[UWP] Setting IsRefreshing from OnAppearing on RefreshView crashes UWP",
+		PlatformAffected.UWP)]
+#if UITEST
+	[NUnit.Framework.Category(UITestCategories.RefreshView)]
+#endif
+	public class Issue8186 : TestNavigationPage
+	{
+		RefreshView _refreshView;
+		protected override void Init()
+		{
+			_refreshView = new RefreshView()
+			{
+				Content = new ScrollView()
+				{
+					Content = new StackLayout()
+					{
+						Children =
+						{
+							new Label()
+							{
+								Text = "If you are reading this and see a refresh circle test has succeeded",
+								AutomationId = "Success"
+							},
+							new Button()
+							{
+								Text = "Push Page then return to this page.",
+								Command = new Command(() =>
+								{
+									Navigation.PushAsync(new ContentPage()
+									{
+										Content = new Button()
+										{
+											Text = "Pop Page",
+											AutomationId = "PopPage",
+											Command = new Command(()=> Navigation.PopAsync())
+										}
+									});
+								}),
+								AutomationId = "PushPage"
+							}
+						}
+					}
+				}
+			};
+
+			var page = new ContentPage() { Content = _refreshView };
+			page.Appearing += (_, __) => _refreshView.IsRefreshing = true;
+			page.Disappearing += (_, __) => _refreshView.IsRefreshing = false;
+			PushAsync(page);
+		}
+
+#if UITEST
+		[Test]
+		public void SetIsRefreshingToTrueInOnAppearingDoesntCrash()
+		{
+			RunningApp.WaitForElement("Success");
+			RunningApp.Tap("PushPage");
+			RunningApp.Tap("PopPage");
+			RunningApp.WaitForElement("Success");
+		}
+#endif
+	}
+}

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

@@ -19,6 +19,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)CollectionViewHeaderFooterTemplate.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)CollectionViewHeaderFooterView.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)CollectionViewItemsUpdatingScrollMode.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue8186.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue3475.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue5354.xaml.cs">
       <SubType>Code</SubType>
@@ -1596,4 +1597,4 @@
       <Generator>MSBuild:Compile</Generator>
     </EmbeddedResource>
   </ItemGroup>
-</Project>
+</Project>

Xamarin.Forms.Platform.UAP/RefreshViewRenderer.cs

@@ -2,6 +2,7 @@
 using System.ComponentModel;
 using Microsoft.UI.Xaml.Controls;
 using Windows.Foundation;
+using Windows.UI.Core;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Media;
 using Xamarin.Forms.PlatformConfiguration.WindowsSpecific;
@@ -41,6 +42,7 @@ namespace Xamarin.Forms.Platform.UWP
 			base.Dispose(disposing);
 		}
 
+		bool _isLoaded = false;
 		protected override void OnElementChanged(ElementChangedEventArgs<RefreshView> e)
 		{
 			if (e.NewElement != null)
@@ -53,13 +55,26 @@ namespace Xamarin.Forms.Platform.UWP
 					};
 
 					refreshControl.RefreshRequested += OnRefresh;
+					refreshControl.Loaded += OnLoaded;
+
+					// Telling the refresh to start before the control has been sized
+					// causes no refresh circle to show up
+					void OnLoaded(object sender, object args)
+					{
+						refreshControl.Loaded -= OnLoaded;
+						_ = Dispatcher.RunAsync(CoreDispatcherPriority.Low, () =>
+						{
+							_isLoaded = true;
+							UpdateIsRefreshing();
+						});
+					}
 
 					// There's a bug with RefreshContainer where if you assign the Visualizer
 					// yourself on creation it will cause RefreshRequested to fire twice
 					// https://github.com/microsoft/microsoft-ui-xaml/issues/1282
 					long callbackToken = 0;
 					callbackToken = refreshControl.RegisterPropertyChangedCallback(RefreshContainer.VisualizerProperty,
-						(_,__) =>
+						(_, __) =>
 						{
 							if (refreshControl?.Visualizer == null)
 								return;
@@ -73,13 +88,14 @@ namespace Xamarin.Forms.Platform.UWP
 
 				UpdateContent();
 				UpdateIsEnabled();
-				UpdateIsRefreshing();
 				UpdateRefreshPullDirection();
 			}
 
 			base.OnElementChanged(e);
 		}
 
+
+
 		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
 			base.OnElementPropertyChanged(sender, e);
@@ -123,6 +139,9 @@ namespace Xamarin.Forms.Platform.UWP
 
 		void UpdateIsRefreshing()
 		{
+			if (!_isLoaded)
+				return;
+
 			if (!Element.IsRefreshing)
 			{
 				CompleteRefresh();